Road Network Performance Monitoring & Management Guideline

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Road Network Performance Monitoring & Management Guideline
Road Network Performance Monitoring &
Management Guideline
Road Network Performance Monitoring & Management Guideline
Quality Record Sheet

        Road Network Performance Monitoring &
                Management Guideline

Authorisation

Project Champion             Peter Higgs, IPWEA

Prepared By                  Henning, Holland and Tapper

Reviewed By                  Waugh

Date                         October 2019
Road Network Performance Monitoring & Management Guideline
CONTENTS

1        This Guideline                                                                              4
         1.1     Objectives of this guideline                                                        4
         1.2     Structure of the Guideline                                                          5

Part I   Context to Performance Monitoring and Management                                            6
2        Performance Management a Critical Part of the Asset Management Processes                    7
         2.1      Asset Management processes                                                         7
         2.2      The business case for performance management                                       8
3        Finding the Optimal Performance Level to Maintain – The Long Term Objective                12
         3.1     Realistic expectations of performance reporting planning applications              12
         3.2     What is a good performance for the road network under different LoS expectations   13
         3.3     Good performance for individual road sections                                      14

Part II Performance Monitoring and Management Process                                               15
4        Data                                                                                       17
         4.1      Data needs and processing                                                         17
         4.2      Recommended data collection frequencies                                           19
5        Frameworks                                                                                  21
         5.1     Key performance frameworks for managing road asset                                  21
         5.2     Additional references to consider                                                  23
         5.3     Available measures                                                                 24
         5.4     Measures, composite indices, and future performance areas                          30
         5.4.1   Performance measures                                                               30
         5.4.2   Composite indices                                                                   31
         5.4.3   Future performance areas / measures                                                33
6        Story                                                                                      35
         6.1     Story-telling                                                                      35
         6.2     Understanding the full statistical distribution                                    35
         6.3     Understanding network condition distribution and distribution changes over time    36
         6.4     Tips for effectively communicating performance measures                            39
7        Business Case Support                                                                      41
         7.1     Linking the performance to investment and maintenance strategy                     41
         7.2     Peer Comparison and Benchmarking                                                   42
         7.2.1   Peer Group Comparisons                                                             43
         7.2.2   Benchmarking using data envelopment analyses                                       43
8        Application                                                                                45
         8.1     Underlying principles of making optimal decisions on an operational level          45
         8.2     Using trends during field investigations / RAPT reviews                            47
9        References                                                                                 49
10       Glossary of Terms                                                                          50

Appendix A Case Study Examples for Level of Service Reporting Frameworks                            54
Appendix B Case Study Example Performance Outputs from Main Road Western Australia                  58
Road Network Performance Monitoring & Management Guideline
TABLE OF TABLES
Table 1: Performance Monitoring Application ............................................................................................................................ 12
Table 2: Data Quality Report on Each Data Items (Source REG) ..................................................................................... 17
Table 3: Tips for Data Processing ...................................................................................................................................................... 18
Table 4: Data collection requirements for performance monitoring (Adapted from Henning et al., 2015) 20
Table 5: Confidence level rating framework for most common road condition data (Henning et al., 2015) 20
Table 6: Relevant Performance Frameworks for RCAs (Road Controlling Authority) .......................................... 22
Table 7: Additional References ........................................................................................................................................................... 23
Table 8: Available Measures ................................................................................................................................................................. 24
Table 9: The advantages and limitations of composite indices ......................................................................................... 32
Table 10: Potential additional composite indices ...................................................................................................................... 33
Table 11: Future Performance Monitoring Area/measures .................................................................................................... 33
Table 12: Condition Distribution ......................................................................................................................................................... 37
Table 13: Changes in Distribution over time – example 1 ....................................................................................................... 37
Table 14: Changes in Distribution over time – example 2 ..................................................................................................... 38
Table 15: Using Performance Monitoring and Reporting in an Investment Strategy ............................................. 41
Table 16: Terms Used in this guideline ............................................................................................................................................ 50

TABLE OF FIGURES
Figure 1: Information Dashboard ...................................................................................................................................................... 4
Figure 2: Resulting Benefits from Performance Management ........................................................................................ 5
Figure 3: The Asset Management Road Map (Henning, 2015) .......................................................................................                                              7
Figure 4: The Investment Approach (Based on Karlaftis and Kepaptsoglou, 2012) ........................................                                                                       8
Figure 5: Application of Performance Monitoring in Respective Asset Management Levels ......................                                                                                 9
Figure 6: Performance monitoring applied to different datasets ................................................................................. 10
Figure 7: Outcomes from relative comparison analyses .................................................................................................... 11
Figure 8: Road network maintenance planning is a balancing act between investment, risk and LoS .. 13
Figure 9: The danger of making maintenance decisions on the basis of condition alone ............................. 14
Figure 10: Linking Grading Frequency to Customer Complaints (Robertson, 2018) ......................................... 19
Figure 11: Related Performance Frameworks to Road Asset Management Levels .............................................. 21
Figure 12: Measures that describe the surface condition .............................................................................................. 30
Figure 13: Measures that describe the pavement make-up and condition ........................................................... 30
Figure 14: A Typical Distribution of SCI for an Urban Authority ................................................................................ 31
Figure 15: Suggested condition ranges for SCI .................................................................................................................. 32
Figure 16: IRAP Star Rating System for Roads (source https://www.irap.org/) ................................................. 33
Figure 17: “The Flaw of Averages” (Savage, 2012) ............................................................................................................ 35
Figure 18: Considering specific statistical percentiles within the full distribution .............................................. 36
Figure 19: Explaining the Box-and-Whisker Graphs ......................................................................................................... 36
Figure 20: Building Blocks for a Business Case (Source IDS Training Material) ................................................. 41
Figure 21: An example of Connecting Performance and Costs (Source Main Roads Western Australia) . 42
Figure 22: Data Envelopment Analysis .................................................................................................................................. 43
Figure 23: Data Envelopment Analyses Results ................................................................................................................ 44
Figure 24: Efficiency Classification of all Local Councils in NZ (Shivaramu, 2018) ........................................... 44
Figure 25: The value of investment into preservations treatments (Source: REG, 2010) ............................... 45
Figure 26: The business process for taking account of modelling outcomes in field decisions ................. 46
Figure 27: Different measures carrying different weightings pending road class (Source IDS) ................. 47
Figure 28: Viewing Condition Trends During Field Inspections (Source Juno Viewer) .................................. 48
Road Network Performance Monitoring & Management Guideline
Figure 1: Information Dashboard

1. This Guideline
Imagine having to fly an aircraft with no instruments. There is some information we would wish
we had at our fingertips!
•   How high am I?
•   Am I going the right way?
•   Will I get lost in a cloud?
•   Will I have enough fuel?

This information will keep us safe, on track, and able to reach our destination successfully.
There is more information we can use if things get a bit rough. Likewise, managing
infrastructure requires complete and accurate information on the full extent of the network, its
performance over time and the costs required to maintain and operate it.

This guideline was developed by the New Zealand Road Infrastructure Management Support
Group (RIMS). It forms part of the Body of Knowledge that provides sector guidelines to assist
road asset managers with the management planning of their assets.

1.1 Objectives of this guideline
Problems / Key Questions
During the need development for this guideline, some common issues raised by a number of
road controlling authorities in New Zealand included:
•   How can performance management be used more effectively in the management and
    maintenance decision making of road assets?
•   How do different performance frameworks relate to each other?
•   How the statistical performance outputs relate to the health of the network, and how
    performance measures relate to different work classes / treatments?
•   What are the linkages between performance outcomes to the appropriate maintenance
    programme and investment profile are not clearly demonstrated?
•   Are agencies fully aware of the data implications on performance monitoring and need
    guidance to the type, frequency, and quality and processing of condition data?

                                                                                                4
Road Network Performance Monitoring & Management Guideline
Aim
The aim of this guideline is to assist authorities in better decision making for investment in
maintenance programmes through performance monitoring, reporting and management. This
aim will be achieved by addressing the following objectives:

1. Improve the understanding of how the network performs through specific measures (what
   they measure, how it can be used) and its performance from a statistical point of view
2. Clarify the performance management implications as viewed from different performance
   monitoring frameworks used in New Zealand, including One Network Road Classification
   (ONRC), Department of Internal Affairs (DIA) and Council specific frameworks
3. Improve the understanding of linking performance outcomes to the appropriate
   maintenance programme and investment profile
4. Define the data implications on performance monitoring and need guidance to the type,
   frequency, quality and processing of condition data

Benefits
A robust performance monitoring and reporting process will result in benefits for the agencies
as illustrated in in Figure 2 below.

Figure 2: Resulting Benefits from Performance Management

                                                                 INCREASED EFFICIENCIES
                                                                 OF MAINTENANCE FUNDS

                                               REDUCED RISKS ASSOCIATED WITH
                                           INAPPROPRIATE MAINTENANCE INVESTMENTS

                              MORE VALUABLE, CONSISTENT AND TRANSPARENT
                                COMMUNICATIONS OF CONDITION OUTCOMES

                       BETTER FOCUSED MAINTENANCE INVESTMENT

1.2 Structure of the Guideline

                                           The Context for Performance Monitoring
                                           and Management
           Part I                          •   Asset managment process
                                           •   Why we monitor performance
                                           •   What performance monitoring could achieve

                                           Performance Monitoring and
                                           Management Process
                                           •   Data Needs
           Part II                         •   Performance Frameworks
                                           •   Telling the Story
                                           •   Business Case Support
                                           •   Application

                                                                                                 5
Road Network Performance Monitoring & Management Guideline
Part I
Context to Performance Monitoring and Management
Road Network Performance Monitoring & Management Guideline
2. Performance Management a Critical Part of the
   Asset Management Processes
2.1 Asset Management processes
Too often asset managers believe they will achieve successful network outcomes by executing
only one of the asset management process well. In fact, by having a balanced approach across
the entire spectrum of asset management activities, a platform of robust linkages is created
between the objectives (including investment strategies) of an organisation and ultimately the
services provided to the community through the asset. Figure 3 illustrates the main activities
involved in road asset management.
Although performance management is specifically indicated within the lifecycle management
grouping, it links to, and could also be categorised in most of the other processes including:

•   The outcomes from the Asset Knowledge (e.g. condition data) is given meaning through
    performance reporting and management
•   Performance outcomes is a crucial part of the over-all decision processes, in particular,
    related to Level of Service (LoS) management
•   Performance monitoring and reporting is a vital process to monitor the asset delivery
    cycle by reporting the outcome of both operations and maintenance. It is also a significant
    component within the procurement processes
•   Lastly, performance monitoring and management is ultimately the communication vehicle,
    reporting on progress with strategies and legislative requirements.

Figure 3: The Asset Management Road Map (Henning, 2015)

                                                                    Customer              Legislation            Investors

                                                                            Institutional Arrangements (Governance,
                                                                               Strategy, Asset Management Plans)
     Enabling People (Skills training and guidelines)

                                                           Decision Making           Lifecycle Management
                                                                                                                        Demand Management

                                                              Pavement                     Lifecycle cost
                                                           management tools                   analysis
                                                                                                                      Disposal           Acquire

                                                                                          Depreciation and                   Lifecycle
                                                            Risk Management                                                  Delivery
                                                                                             valuation

                                                                                                                      Maintain           Operate
                                                                                            Performance
                                                             Level of Service
                                                                                            Management

                                                                                                                             Procurement

                                                        Asset Knowledge (Road Hierarchy, Database, Inventory and Condition Data)

                                                                                                                                                   7
Road Network Performance Monitoring & Management Guideline
2.2 The business case for performance management

  Why?
  We report on the outcome of road investment in order to make better decisions towards
  providing the travelling public with the service they require at an affordable, sustainable,
  and optimal cost.

Figure 4 illustrates the investment approach where we apply inputs to achieve outputs and
outcomes. The systems used to convert the inputs into outputs require monitoring to ensure
the investment is appropriate and the results will contribute to the outcomes we seek from
the system.

Figure 4: The Investment Approach (Based on Karlaftis and Kepaptsoglou, 2012)

                                                             USER CONDITIONED
                                                                OUTCOMES

                 HUMAN          ACTIVITY       PHYSICAL
               SUBSYSTEM       SUBSYSTEM      SUBSYSTEM
                                                                                     VALUES

   INPUTS

                           ROAD ADMINISTRATOR
                                                                 OUTPUTS

                                                               CONCOMITANT
                                                                 OUTPUTS

                                                                                                 8
Road Network Performance Monitoring & Management Guideline
What?
  Performance monitoring and reporting have to assist decision processes at a strategic /
  investment level while informing programming and planning processes on tactical and
  operational levels.

Figure 5 illustrates the three levels of management and planning in asset management and the
typical questions performance management are able to cover.

Figure 5: Application of Performance Monitoring in Respective Asset Management Levels

                                           • How does the actual performance
                                             compare to target levels?
                                           • Is the investment targeting the right
                                             outcomes?
                                           • Are investment levels sustainable?
                                           • Are the risks appropriately managed?

                                           • Ensure sustainable investment levels
                                           • Timing and type of renewal and
                                             maintenance
                                           • Linking technical inputs to
                                             performance outcomes

It is vital to monitor the achievement level of the outputs and outcomes sought. This tests if
the investment and methods we use are fit for purpose, and builds onto our evidence base for
future decision making.

                                                                                             9
How?
  •   “Snapshot” performance reporting – is usually relative to performance targets. This
      technique is often used in Customer LoS reporting;
  •   Trend Monitoring – tracking the change in the performance of the network over time;
      “has it got better or worse”, and,
  •   Benchmarking – a process of comparing to targets being set on the basis of other
      peer organisations “I want to be as good as that team”.

In order to answer the different asset management questions, performance reporting is
undertaken using different data sets as illustrated in Figure 6. The figure also shows the
different purposes for the respective monitoring processes.

Figure 6: Performance monitoring applied to different datasets

                                                                                             10
In some cases we have known target performance levels – in other cases, we have to rely
  on benchmarking ourselves to others. Keep in mind that “good” performance is relative to
  the type of comparison used.

Figure 7 shows the potential outcome of relative comparison analyses. It shows the value of
undertaking internal performance comparisons, say comparing current performance to set
target performance levels, combined with comparing with external authorities. Combining
internal performance comparisons to external comparisons daylight the appropriateness of
defined target performance levels. For example, my authority may be performing very well
to internally defined targets, but when compared to other authorities, we may find that my
authority is over or underperforming.

Figure 7: Outcomes from relative comparison analyses

Note: Over-performance to internal targets and external comparison could also be classified as
being a bad outcome.

                                                                                              11
3. Finding the Optimal Performance Level to
   Maintain – The Long Term Objective of
   Asset Management
3.1 Realistic expectations of performance reporting planning applications
Section 2.1 describes how performance monitoring and management has relevance in most
of the processes and steps involved with the entire asset management process. Because
performance reporting is so widely used, it often results in unrealistic expectations of what
reporting on performance is able to tell us. Table 1 lists the range of application areas for
performance monitoring and subsequent sections go into the application in more detail.
Applications are further discussed in Section 8.

Table 1: Performance Monitoring Application

                                                                 Additional Processes /
                                 What performance                considerations required
Performance Questions
                                 reporting is able to tell us    to answer performance
                                                                 questions

What is the overall network      What standard is being          Suggested target
/ subnetwork performance         achieved?                       performance levels are also a
levels or targets we should      General indications or          combination of:
aim for?                         suggested trends in future      • Available funding: short,
                                 performance                        medium and long-term;
                                 What was the past               • What are the performance
                                 performance of the network         expectations from the
                                 What is the current                community;
                                 performance or performance      • What are the risks we
                                 distribution of the network        need to manage
                                 How does my authority’s         • The expected / forecasted
                                 performance compare                performance for each road
                                 to others                          link into the future

What is the optimal              Through performance             An optimised maintenance
maintenance regime on            reporting and benchmarking      programme for different
a network?                       techniques, we are able to      investment levels requires
                                 report on efficiencies          forecasted performance
                                                                 modelling, lifecycle analyses
                                                                 and optimisation techniques

What is the best treatment     Performance management            This is not a static answer
on a road section at any point can only be used for fixed        because it requires
in time?                       decision algorithms that do       the knowledge of past
                               not optimise a programme as       performance, available
                               they often resort to a “worse     funding (on a network
                               first” approach                   level) and taking account
                                                                 of road function and user
                                                                 expectations

                                                                                                 12
3.2 What is a good performance for the road network under different
    LoS expectations

    “Good performance” can only be defined in the context the situation the network serves

Figure 8 shows LoS, investment and risk being an interlinked system for planning and managing
road maintenance and renewals. While, each one of these elements could be considered in
isolation using performance reporting, the interactions between these elements are more
complex and for that forecasted outcomes, Lifecycle cost and optimisation are needed to
determine the optimum outcomes.

Often the status quo becomes the default level of service, as that is what customers are used
to receiving. However, if there is a significant service level gap, the customers have already
made it clear that the existing level of service is not satisfactory. In this situation, the default
level of service is the anticipated improved service. This approach is embraced by the ONRC
philosophy where an asset serving a function in one location should perform similar wherever
that asset / network is. When looking at network performance it is important to consider – is
this a network issue or a local issue? Extrapolating localised issues across the network is not a
helpful intervention strategy.

While roading authorities have traditionally chosen the Level of Service that will be provided,
along with the level of risk that is acceptable, there has then been some change in securing the
corresponding investment.

Figure 8: Road network maintenance planning is a balancing act between investment, risk and LoS

                                              LoS

                  Investment                                         Risk

                                                                                                  13
3.3 Good performance for individual road sections
As much as we are unable to use performance monitoring and reporting for determining
the network maintenance and renewal programme, the same applies to making decisions on
individual road sections. Some of the reasons why it is dangerous to only use historic and
performance data for decision are:

•   Although engineers have the skills for making an appropriate engineering decisions on
    maintenance or renewal needs for individual road sections, it is difficult to make a decision
    on an individual road section while thinking of its relationship to available funding and all
    the other road sections on the network. It is thus not surprising that maintenance and
    renewal programme solely based on field processes and condition reporting often resort
    back to a “worse first strategy”;
•   Likewise, engineers are often unable to bring life-cycle costing into consideration when
    making maintenance decisions for individual road sections. The main decision is not only
    related to “what is the most appropriate choice of treatment now”, but often it is rather
    important to know how the current decision will impact on future maintenance cost.

Figure 9 provides an example of using a fixed performance level for making maintenance
decisions. Assume for this example that both road sections carry equal traffic and also have the
same functional classification. Just because the two road sections reach the same condition
threshold at the same time, does not mean that a common treatment or treatment timing
would have a good outcome for both road sections. It perhaps would have made more sense
to apply a preservation treatment much earlier to Road Section A in order to arrest the fast
deterioration rate.

Figure 9: The danger of making maintenance decisions on the basis of condition alone

A more holistic approach for field decision that incorporates input from an array of
considerations or “decision lenses”, is explained in Section 8.2.

                                                                                                14
Part II
Performance Monitoring and Management Process
Part II Sections

              4.1   Data needs and processing
   Data
              4.2   Recommended data collection frequencies

              5.1   Key performance frameworks for managing the road asset
              5.2   Additional references to consider
Frameworks
              5.3   Available measures
              5.4   Measures, composite indices, and future performance areas

              6.1   Story-telling
              6.2   Understanding the full statistical distribution
              6.3   Understanding network condition distribution & distribution
  Story             changes over time
              6.4   Tips for effectively communicating performance measures

              7.1   Linking the performance to investment and maintenance strategy
 Business     7.2   Peer Comparison and Benchmarking
  Case
 Support

              8.1   Underlying principles of making optimal decisions on
                    operational level
Application   8.2   Using trends during field investigations / RAPT reviews

                                                                                     16
4. Data
                                                                                                             Business
                                       Data                 Frameworks                   Story               Case                       Application
                                                                                                             Support

4.1 Data needs and processing
                             “Public organisations that manage their information well will treat data as a strategic asset. This
                             means that they recognise its value and that they have a deliberate strategy for how they manage
                             and govern information.” (Controller & Auditor General, 2018).

There is an obvious and direct relationship between the quality of performance reporting and the quality of the
data. For that reason, it is good practice to report on the data quality as part of any performance reporting. A
simple example of this is the data quality tables provided with asset valuation reports.
The Road Efficiency Group (REG) data quality tools are perfect for more thorough reporting on these issues.
Table 2 shows an example of data quality reporting from the REG tool. It is good practice to report on the
data quality of each of the data items used in a performance monitoring and reporting process. Also, note that
reporting on data quality needs to include both inventory data items and the performance measures used.

Table 2: Data Quality Report on Each Data Items (Source REG)

                                     Ref        Probable Metrics                       Primary      Secondary      Initial 2016/17 National Result &
Category

                  Category

                                                                                       Dimension    Dimension(s)   Comments
                  Sub-

                                     AM-TL2     Treatment length sectioning            Timeliness   Accuracy
                                                maintained
                  Treatment Length

                                                                                                    Completeness
                                                Percentage of treatment length
                                                records added or updated during
                                                last three financial years. Excludes
Network

                                                pavement type “U” and disabled                                     The result is a lot higher than expected
                                                treatment lengths                                                  and very similar to AM-Ca2. This needs
                                                                                                                   to be explored further
                                     AM-Su1ba   Achieved chipseal resurfacing          Complete-    Timeliness
                                                renewal programme as-builted           ness         Consistency
                                                Percentage of achieved chipseal
Asset Inventory

                                                resurfacing renewals reported in TIO
                                                and as-builted in RAMM (in m2) for
                  Surfacing

                                                reported financial year                                            Significantly more data loaded to RAMM
                                                                                                                   than reported as achieved in TIO. Script
                                                                                                                   needs to be updated to included surfaces
                                                                                                                   with appropriate works origin / category only
                                     AM-Su1bb   Achieved asphaltic concrete            Complete-    Timeliness
                                                resurfacing renewal programme as-      ness         Consistency
Asset Inventory

                                                builted
                                                Percentage of achieved asphaltic
                                                concrete resurfacing renewals
                  Surfacing

                                                reported in TIO and as-builted in                                  Same as AM-Su1ba. Larger variation
                                                RAMM (in lane.km) for reported                                     largely due to the smaller quantities
                                                financial year
                                     AM-Su4     Surface records have valid attribute     Accuracy
                                                data
                                                Percentage of treatment length records
Asset Inventory

                                                with top surface records with a valid
                                                chip size (AM>=7, CS
The quality of performance reporting is also a function of appropriate data processing
techniques. Table 3 provides some useful tips for data processing.

Table 3: Tips for Data Processing

Processing Aspect Why is this Important?                   Recommended Practice
Data Aggregation /      To be statistically robust in      Use consistent 100 or 200m lengths. The ONRC
reporting intervals     processing requires working        performance reporting tool uses 100m lengths
                        with consistently base data
                        sectioning lengths. Given
                        the length and changing
                        nature of treatment lengths,
                        using treatment lengths
                        is not appropriate for
                        statistical reporting
Time-Based Analysis –   Readers should be aware that       Use annual snapshot data in order to allow for
Network Changes         the RAMM data structure is not     time-based changes – e.g. when surface types
                        temporal. Therefore for specific   change. Note that the annual snapshot will be a
                        analyses such as “how long do      time slice of the data at a given point of inventory
                        my surfaces last” care should      and condition data. As the different data items are
                        be taken that the appropriate      collected at different frequencies and at a different
                        surface types are matched          time of the year, the timing of such a snapshot is
                        to the performance data            important. e.g. the condition data has to relate to an
                        and dates                          updated inventory.
Time-Based Analyses     In the past, some authorities      Undertake full network analysis or when a sampled
/ trend – Network       used sampled surveys. For          (e.g. road class) sampling is used, do separate
Sampling                example, they may have             performance trend analyses on consistently measured
                        covered only 1/3 of the            samples. For trends to be valid, it has to be based on
                        network for annual roughness       continuously monitored parts of the network. E.g. if a
                        surveys. Inconsistent condition    network is split into 3 parts (say a, b and c). With “a”
                        monitoring samples cannot          being surveyed every year and b and c in alternating
                        be used for trend analyses         years, valid trend analysis can only be undertaken
                        and have limited value for         on “a”, “b” and “c” in sepearte analysis sets, not as a
                        “snapshot” or “latest” data        combined analysis set.
Frequency of            Industry minimum data              The ultimate purpose of trend analyses should
Measurements            collection requirements            be considered for deciding on the data collection
                        often limit trend analyses. A      frequency. For example, with the NLTP cycle being
                        minimum of three data points       in three-year blocks, collecting the data only once
                        is required for any meaningful     during the three years, will have limited value (weak
                        trend analyses                     evidence) for trend analysis.
Check data quality /    Completed condition data           Validation of trend analyses should prove that
validation not only     collection surveys do not          observed trends are actual and not subject to bias
completeness            necessarily mean the data          within the measurements itself. Simple checks should
                        quality is good                    include checking for outliers and correlations between
                                                           maintenance quantities and condition outcomes.
Contextual Data         Trend analyses needs to be         Always include routine maintenance cost trends
                        fully supported by contextual      alongside condition trends. Significant shifts in
                        data that may have impacted        condition performance also need to be supported
                        the trends                         / explained by presenting potential causing factors,
                                                           such as changed or excessive rainfall patterns and /
                                                           or usages such as significant loading increases due to
                                                           timber logging or dairy expansions.
Meaningful reporting    Condition trends by themselves     Correlation between different trends increases the
                        are seldom meaningful. It is       understanding and value of reporting. Figure 10
                        good to connect reporting to       is an example that suggests an initial increase in
                        the end-customer                   customer complaints when the blading frequency has
                                                           changed, yet over time the new LoS is accepted and
                                                           complaints reduced.

                                                                                                                   18
Figure 10 is an example that suggests an initial increase in customer complaints
when the blading frequency has changed, yet over time the new LoS is accepted and
complaints reduced.

Figure 10: Linking Grading Frequency to Customer Complaints (Robertson, 2018)

Note: The data for 2018 does not include a full financial year, complaints were not recorded
prior to 2011. Complaints data were only incorporated since 2011

4.2 Recommended data collection frequencies
Condition data collection returns significant benefits for the investment, yet Authorities
monitor the cost of data collection because of the perception that data collection does not
necessarily result directly in “fixing roads”. The NZTA research report (Henning et al., 2015) on
performance monitoring produced Table 4 and Table 5, which included suggested minimum
data collection practices for the purpose of performance reporting and management.

                                                                                                19
Table 4: Data collection requirements for performance monitoring (Adapted from Henning et al., 2015)

Functional Road              Data confidence level
                                                             Survey frequency          Data items
Classification               (see Table 5)

National                     4                               Annual                    Full HSD

Regional                     4                               Annual                    Full HSD

Arterial                     4                               Annual                    Full HSD

Primary collector            4                               2 years                   Full HSD

Secondary collector          3                               2 years                   Full HSD

Access                       3                               2 years                   R&R and FWD

Access Low Volume            3                               2 years                   Visual

Legend: Full HSD = roughness, rutting, texture, skid, FWD (50 to 100% cover)
        R&R and FWD= roughness, rutting and Falling Weight Deflectometer (33%% sample)

Table 5: Confidence level rating framework for most common road condition data (Henning et al., 2015)

                                                    Confidence rating
Confidence factor
                           Very low (1)        Low (2)                 Medium (3)            High (4)

Equipment sophistication Visual                Automated – non         Automated laser       Automated laser
                                               laser

Calibration standard       No calibration      Internal calibration    Contractual           Calibrated
                                                                       calibration process   according to NZTA
                                                                                             state highway
                                                                                             standards

Quality assurance (QA)     No evidence of QA   Internal QA             Contractual QA, eg    Calibrated
                                                                       loop method           according to NZTA
                                                                                             state highway
                                                                                             standards

Post survey confirmation   None                Compare overall         Consider individual Benchmark with
                                               network trends          sections and        LTPP sites
                                                                       exception reporting

Note: the overall rating is calculated as the average score from each confidence factor

                                                                                                               20
5. Frameworks
                                                                     Business
        Data           Frameworks           Story                    Case           Application
                                                                     Support

5.1 Key performance frameworks for managing road asset

   Councils have to consider performance reporting for different organisations; the
   questions are how do they relate to Councils’ network performance. This section puts
   these frameworks into perspective.

Performance may be measured for internal business / Council needs or to meet the reporting
requirements of other agencies, such as the Department of Internal Affairs and NZTA. The
performance of the asset also needs to be understand to inform decision-making on how the
asset can be best managed.

Figure 11 shows the different performance frameworks currently in use within the sector and
where it fits in relation to the respective asset management processes. Of these frameworks,
the ONRC and Council specific performance measures cover the entire asset management level
spectrum. Appendix A demonstrates how Auckland Transport have integrated their own and
ONRC reporting frameworks. The focus of the DIA and Wellbeing Framework are at a national
level and thus not necessarily integrated at the local level.

Figure 11: Related Performance Frameworks to Road Asset Management Levels

                                                            TREASURY
                                                        LIVING STANDARDS
                                                           FRAMEWORK

                                              COUNCIL OUTCOME     COUNCIL OUTCOME
                                               AND OBJECTIVES      AND OBJECTIVES

                                              COUNCIL LEVEL OF      NON-FINANCIAL
                                             SERVICE REPORTING      PERFORMANCE
                                              AND MONITORING        MEASURE (DIA)

                                                       ONE NETWORK ROAD
                                                         CLASSIFICATION
                                                         PERFORMANCE
                                                           MEASURES

                                                                                                  21
The following examples of Performance Management Frameworks illustrate the range of
approaches in use, and the differences between measuring inputs, outputs and outcomes.

Table 6: Relevant Performance Frameworks for RCAs (Road Controlling Authority)

                                                                                Relevance to
Framework           Description
                                                                                Managing Roads

Treasury Living     Being relatively new the LSF is setting the pace at the     Although not widely used
Standards           national level for government entities to report the        within transport performance
Framework (LSF),    impact of policies and investment into four impact areas    monitoring frameworks,
(Treasury, 2015)    (capitals), economic, natural, social and human             there will be a drive towards
                                                                                more consistent reporting
                            Assess the impact of policy across key              in these areas in future
                                 living standards dimensions                    activity management plans.
                                                                                Opportunities should be
                                                                                maximised to relate road
                                                                                infrastructure reporting to
                                                                                LSF capitals
                                          HIGHER LIVING
                                           STANDARDS
                                         • Economic capital
                                           • Natural capital
                                            • Social capital
                                           • Human capital

Department of       The rules for non-financial reporting measures came         The Department of Internal
Internal Affairs    into force on 30 July 2014 under the Local Government       Affairs performance
Non-financial       Act 2002. Through these rules, Councils are obligated to    measures are included in
Performance         report on certain performance measures as part of their     the Councils’ Long-term
Measures            asset management process.                                   Plan and asset management
                                                                                planning process. Although
                    Performance measures to report on include:
                                                                                at a strategic level, these
                    1.   How safe are the local roads?                          measures are actively
                    2.   What is the overall condition of sealed roads in the   managed and monitored
                         local road network?                                    through delivering tactical
                                                                                performance measures
                    3.   Is the sealed roads network being maintained
                                                                                that feed into the
                         adequately?
                                                                                strategic outcomes
                    4.   Are the footpaths that form part of the local road
                         network being maintained adequately?
                    5.   Does the local authority responsible for the service
                         provide a timely response if there is a problem?

One Road Network    Developed as part of Road Efficiency Group’s (REG)          The ONRC reporting
Performance         ONRC initiative a set of expected performance measures      framework is foundational in
Frameworks (ONRC)   were developed for each respective ONRC class. These        the in the strategic planning
                    measures are broadly categorised according to the           and reporting of road
                    following customer outcome measures:                        investment outcomes.
                    • Amenity                                                   Maintenance planning
                    • Accessibility                                             processes resulting in the
                    • Efficiency                                                quantity, type and timing
                    • Resilience                                                of maintenance ultimately
                    • Travel Time                                               has to be checked against
                    • Safety                                                    achieving the state
                    The Auckland Transport case study (Appendix A)              customer outcomes
                    illustrates how the ONRC framework is integrated with
                    the Council specific LoS performance framework

                                                                                                             22
Relevance to
Framework              Description
                                                                                  Managing Roads

Council Specific       Councils will have specific performance monitoring         Specific tactical performance
Level of Service       frameworks that incorporate the ONRC framework but         measure targets are specified
Monitoring and         add some specific Councils specific objectives. Most       to ensure:
Reporting              Councils will add asset preservation type measures to      • ONRC customer
                       ensure sustainable maintenance programmes                      outcomes are met
                                                                                  • The road network is
                                                                                      maintained at an optimal
                                                                                      and sustainable manner

5.2 Additional references to consider
Table 7: Additional References

Reference                         Description and Value to NZ Authorities

OECD Performance Measurement It provides an excellent summary of performance frameworks used in the
in The Road Sector: A Cross-      USA, Canada, NZ & Australia and Japan. It also provides many examples of
Country Review of Experience      performance measures to use for:
(Karlaftis and Kepaptsoglou 2012)
                                  • Pavement and structure preservation
                                  • Operational Efficiency
                                  • Capacity Expansion
                                  • Safety and the Environment
                                  • Sustainability

AP-T176 / 11 - Network            Some good examples of developed composite indices for the overall
Performance Indicators – Next     performance of pavements, surfaces, safety and efficiency
Generation (Chin, et al., 2011)

Guide to Asset Management         The guideline provides an over-all road asset management approach. It is
(Hassan, et al., 2018)            a good explanation of how performance monitoring and reporting is used
                                  within strategic and tactical asset management

ONRC – Best Practise Guides       There are a number of ONRC guidelines that provides significant guidance
(Obtainable from https://www.     on performance monitoring and applying performance measures in planning.
nzta.govt.nz/roads-and-rail/      Some of the most relevant are:
road-efficiency-group/resources/)
                                  • Auckland Transport Auckland Transport ONRC Gap Analysis: a
                                      project plan
                                  • Lag measures vs real-time measures
                                  • Reporting on mandatory non-financial performance measures – a
                                      Waikato guideline
                                  • Incorporating ONRC into asset management planning
                                  • Bridge management framework

AP-T84 / 07 Application of the    The analytic hierarchy process is a decision technique that uses
Analytic Hierarchy Process in     performance measures in decision making. For example, it considers the
Road Asset Management: User       different impact areas of roughness (e.g. preservation, LoS and safety) for
Manual (Su and Hassan, 2007)      ranking interventions

                                                                                                                23
5.3 Available measures
The following table combines the suites of measures typically used by roading asset managers. It should be noted that the ONRC output
measures are operational / tactical, while the outcome measures are more strategic. The outcome measures consider the performance of
the transport system overall, while the output measures are more asset specific.

Table 8: Available Measures

                                                                          Snapshot (S),     Level of Influence    Works that
                                                                                                                                       Review
Category           Measure                  Description                   Trends (T) or   Business   Mtce         Impacts on this
                                                                                                                                       Comments
                                                                          Benchmark (B)   Case       Planning     measure
Framework: ONRC
Safety Customer    Number of fatal and      The total number of fatal     S, T, B         Major      Minor        Strategic – safety   Direct measure of
Outcome            serious injuries         and serious injuries / yr                                             programme            safety outcomes
                                                                                                                  investment. Black
                                                                                                                  spot improvements
                   Collective risk (fatal   Intensity measure – that      S, T, B         Major      Minor        Strategic – safety   Direct measure of
                   and serious injury)      highlights dangerous routes                                           programme            safety outcomes
                   rate / km                or parts of the network                                               investment. Black    for specific parts of
                                                                                                                  spot improvements    the network
                   Personal risk            The total number of fatal     S, T, B         Major      Minor        Strategic – safety   Direct measure of
                   (fatal and serious       and serious injuries by                                               programme            safety outcomes
                   injury rate by           traffic volume / yr                                                   investment. Black    for specific parts of
                   traffic volume)                                                                                spot improvements    the network
Safety Technical   Permanent hazards        The number of permanent       S, T, B         Minor      Intermediate Marking of hazards   Specific output
Output                                      hazards that are not                                                                       focus
                                            marked in accordance with
                                            national standards (e.g.
                                            building / narrow bridge
                                            within the road corridor)
                   Temporary hazards        The number of sites           S, T, B         Minor      Minor        Contractual          Specific output
                                            inspected and the number                                              compliance           focus, indicative of
                                            of audits compliant with                                                                   network
                                            COPTTM
                   Sight Distances          The number of locations       S, T, B         Minor      Intermediate Minor safety works   Specific output
                                            where sight distance or                                                                    focus, indicative of
                                            signs are obstructed                                                                       network

                                                                                                                                                         24
Snapshot (S),     Level of Influence    Works that
                                                                                                                                         Review
Category           Measure               Description                     Trends (T) or   Business   Mtce         Impacts on this
                                                                                                                                         Comments
                                                                         Benchmark (B)   Case       Planning     measure
                   Loss of control on    The number of fatal and         S, T, B         Major      Minor        Skid treatments and /   Specific output
                   wet roads             serious injuries attributable                                           or curve re-alignment   focus, indicative of
                                         to the loss of driver control                                                                   network
                                         (including on wet roads)
                   Loss of driver        The number of fatal and         S, T, B         Major      Minor        Signs, lighting, Skid   Specific output
                   control at night      serious injuries which occur                                            treatments and / or     focus, indicative of
                                         in crashes at night                                                     curve re-alignment      network
                   Intersections         The number of fatal             S, T, B         Minor      Minor        Skid treatments         Specific output
                                         and serious injuries at                                                                         focus, indicative of
                                         intersections                                                                                   network
                   Hazardous faults      The number of hazardous         S, T, B         Minor      Intermediate Routine maintenance,    Specific output
                                         faults which require evasive                                            Minor safety works      focus, indicative of
                                         action by road users (e.g.                                                                      network
                                         large pothole)
Safety Technical   Cycle path faults     The number of cycle path        S, T, B         Minor      Intermediate Routine maintenance,    Direct measure of
Output                                   hazards requiring evasive                                               Minor safety works      safety outcomes
                                         action by cyclists                                                                              for specific users
                   Vulnerable users      The number of fatal and         S, T, B         Major      Minor        Strategic – safety      Direct measure of
                                         serious injuries involving                                              programme               safety outcomes
                                         vulnerable users                                                        investment. Black       for specific users
                                                                                                                 spot improvements
                   Roadside              The number of locations         S, T, B         Minor      Minor        Inspection Routine      Specific output
                   obstructions          where there are                                                         maintenance             focus, indicative of
                                         unauthorised items placed                                                                       network
                                         within the road reserve
Resilience         Number of journeys    The number of unplanned     T                   Major      Major        Bridge capacity         Impact of local
Customer           impacted by           road closures and the                                                   Drainage                issues on network
Outcome            unplanned events      number of vehicles affected                                             Improvements            performance
                                         by closures
                   Number of             The number of unplanned     T                   Major      Major        Bridge capacity       Impact of local
                   instances where       road closures and the                                                   Drainage              issues on network
                   road access is lost   number of vehicles affected                                             Improvements          performance
                                         by closures where there                                                 Creation of emergency
                                         was no viable detour                                                    route redundancy

                                                                                                                                                           25
Snapshot (S),     Level of Influence   Works that
                                                                                                                                    Review
Category           Measure             Description                    Trends (T) or   Business   Mtce        Impacts on this
                                                                                                                                    Comments
                                                                      Benchmark (B)   Case       Planning    measure
Amenity –          Smooth Travel       % of travel on sealed roads    S, T, B         Minor      Minor       Localised repairs or    Direct measure of
Customer           Exposure (STE)      which are smoother than a                                             full rehabilitation and outcomes. Strong
Measures                               defined threshold                                                     smoothing treatments link to customer

                   Peak roughness      The 85th and 95th              S, T, B         Minor      Minor       Localised repairs or    Direct measure of
                                       percentile roughness of                                               full rehabilitation and outcomes. Strong
                                       your roads                                                            smoothing treatments link to customer

                   Average Roughness   Average Roughness (IRI)        S, T, B         Minor      Moderate    Rehabilitation         Direct measure of
                                       measured by laser or                                                  (smoothing             outcomes. Impacts
                                       Bump integrator                                                       treatments such as     directly on drivers’
                                                                                                             granular or asphalt    perception and
                                                                                                             overlays)              comfort
                                                                                                                                    (Not always an
                                                                                                                                    indication of road
                                                                                                                                    deterioration. It is
                                                                                                                                    heavily impacted
                                                                                                                                    by topography
                                                                                                                                    and urban / rural
                                                                                                                                    differences)

                   Aesthetic faults    The number of aesthetic        S, T            Minor      Major       The full spectrum of   Specific output
                                       faults that detract from the                                          maintenance options    focus, indicative of
                                       customer experience                                                                          network

Accessibility      The proportion      The proportion of each         S, B            Major      Minor       Rehabilitation         Impact of local
- Customer         of network not      road classification that is                                                                  issues on network
Outcome            available to:       not accessible to Class                                                                      performance
                   a. Class 1 heavy    1 Heavy Vehicles and                                                                         (Subjective and
                   vehicles            50MAX vehicles                                                                               a function of risk
                                                                                                                                    tolerance)
                   b. 50MAX vehicles

Accessibility-     Accessibility       The number of instances        T               Minor      Minor       Traffic Services       Specific output
Technical Output                       where the road is not                                                 Marking                focus, indicative of
                                       marked in accordance with                                                                    network
                                       national standards

                                                                                                                                                     26
Snapshot (S),    Level of Influence   Works that
                                                                                                                                   Review
Category          Measure               Description                   Trends (T) or                         Impacts on this
                                                                                      Business   Mtce                              Comments
                                                                      Benchmark (B)                         measure
                                                                                      Case       Planning

Travel Time       Output at indicator   The hourly traffic volume     T, B            Major      Minor      Contract to            Impact of local
Reliability       information sites     during the peak morning                                             encourage night        issues on network
Customer                                hour and peak afternoon /                                           works                  performance
Outcome                                 evening hour                                                                               Strong customer
                                                                                                                                   focus

Cost Efficiency   Pavement              The total quantity and cost   S, T, B         Major      Major      Rehabilitation         Lag indicator of
                  rehabilitation        of pavement rehabilitation                                                                 network health and
                                                                                                                                   preservation

                  Chipseal resurfacing The total quantity and         S, T, B         Major      Major      Resurface              Lag indicator of
                                       cost of sealed road chip                                                                    network health and
                                       seal resurfacing                                                                            preservation

                  Asphalt resurfacing   The total quantity and        S, T, B         Major      Major      AC Resurface           Lag indicator of
                                        cost of asphaltic sealed                                                                   network health and
                                        road resurfacing                                                                           preservation

                  Unsealed road         Total quantity and cost       S, T, B         Major      Major      Maintenance, grading   Lag indicator of
                  metalling             of metalling that has                                               and re-gravelling      network health and
                                        been undertaken over                                                                       preservation
                                        the previous year as
                                        renewal work

                  Overall network       The overall cost per km and S, T, B           Major      Minor      All                    Lag indicator of
                  cost, and cost by     vkt of routine maintenance                                                                 network health and
                  work category         activities, and cost by work                                                               preservation
                                        category on each road

                                                                                                                                                   27
Snapshot (S),     Level of Influence    Works that
                                                                                                                                       Review
Category            Measure             Description                    Trends (T) or                           Impacts on this
                                                                                       Business   Mtce                                 Comments
                                                                       Benchmark (B)   Case       Planning     measure

Framework: DIA

Road Safety         Crash rate trend    The change from the            T               Minor      Intermediate Safety improvements     Direct measure of
                                        previous financial year in                                                                     safety outcomes
                                        the number of fatalities
                                        deaths and serious injury
                                        crashes injuries

Road Condition      Smooth Travel       % of travel on sealed roads    S, T, BM        Minor      Minor        Localised repairs or    Direct measure of
                    Exposure (STE)      which are smoother than a                                              full rehabilitation and outcomes
                                        defined threshold                                                      smoothing treatments Impacts directly on
                                                                                                                                       drivers’ perception
                                                                                                                                       and comfort
                                                                                                                                       (Not always an
                                                                                                                                       indication of road
                                                                                                                                       deterioration. It is
                                                                                                                                       heavily impacted
                                                                                                                                       by topography
                                                                                                                                       and urban / rural
                                                                                                                                       differences)

Maintenance         Maintenance of      The percentage of the          S, T            Minor      Minor        Resurfacing             An indication
planned vs actual   a sealed local      sealed local road network                                                                      of effective
                    road network        that is resurfaced (as                                                                         programme
                                        compared to the target                                                                         delivery
                                        area set in the Asset
                                        Management Plan)

Footpath            The proportion of   The percentage of              S, T            Major      Major        Footpath                Outcome measure,
Conditions          footpaths above     footpaths within a territorial                                         maintenance and         noting result is
                    LoS expectation     authority district that fall                                           renewals                relative to authority
                                        within the level of service or                                                                 defined LoS
                                        service the standard for the
                                        condition of footpaths

                                                                                                                                                        28
Level of Influence
                                                                           Snapshot (S),                          Works that
                                                                                                                                      Review
Category             Measure                Description                    Trends (T) or                          Impacts on this
                                                                                           Business   Mtce                            Comments
                                                                           Benchmark (B)                          measure
                                                                                           Case       Planning

Framework: Additional useful
measures

Asset Preservation   75th Percentile        75th rutting value as          S, T, BM        Major      Major       Rehabilitation      A strong indicator
                     Rutting                measured by High-speed                                                                    of pavement health
                                            data collection                                                                           (Requires HSD
                                                                                                                                      survey)

Safety               Network portion        The network portion of         S, T, BM        Minor      Major       Localised repairs   Direct impact
                     above Peak Rutting     rutting exceeding 15 mm                                                                   measure for wet-
                                            that may lead to water                                                                    road crashes
                                            ponding and unsafe driving
                                            conditions

Asset Preservation   Surface Condition      The composite index            S, T, BM        Major      Major       Resurfacing         An overall
                     Index (SCI)            for surfacing defects as                                                                  measure of surface
                                            calculated by NZTA                                                                        condition
                                                                                                                                      (Does not
                                                                                                                                      indicate specific
                                                                                                                                      surface issues)

Customer             A portion of the       Relative measures as per       S, T            Major      Minor       All maintenance     Customer
LoS Life-cycle       network in very        LoS definition for authority                                          treatments          perception focused
Management           poor condition (e.g.                                                                                             (Subjective
                     95th Percentile)                                                                                                 and relative to
                                                                                                                                      specific council)

                                                                                                                                                     29
5.4 Measures, composite indices, and future performance areas
Performance monitoring and measurements are rapidly developing as our understanding of
the questions and the problems we encounter increase, technology to measure improves,
and our ability to report and convey performance reporting improves. This section provides
some general guidance on the future development of measures and the way in which we
report them.

5.4.1 Performance measures
Asset performance can be measured using different methods and technology. A key
discussion for the network manager is to ascertain what measures are useful and what will
inform decision-making.

Figure 12: Measures that describe the surface condition

                                                                        CRACKING
                                                                        • LONGITUDINAL
                                                                        • LATERAL
                                                                        • ALLIGATOR

                                                                        RAVELLING

                                                                        POTHOLES

                                                                        POTHOLE PATCHES

                                                                        FLUSHING

Figure 13: Measures that describe the pavement make-up and condition

Note: SNP is the modified structural number, curvature is the shape of the deflection bowl as
measured by the falling weight reflectometer
Adapted from https://kids.britannica.com/students/assembly/view/19289

                                                                                             30
5.4.2 Composite indices
Performance measures are often referred to as the quantified values of individual distress
mechanisms, indices are often used to combine these measures into a single number.
Composite indices are very useful to describe an overall outcome that aggregates a number of
different individual indicators or performance measures. An example of the most widely used in
New Zealand is the Surface Condition Index (SCI) that combines a number of surfacing defects
to provide an over-all surface health indicator.

The factors included in the SCI are:
•   cracking (from alligator in RAMM
•   ravelling (from scabbing in RAMM)
•   potholes
•   pothole patches
•   flushing
•   surface age in years
•   expected surface (design) life in years

Figure 14 provides a typical urban network surface condition distribution as expressed by SCI.
Figure 15 gives the condition suggested ranges for the SCI.

Figure 14: A Typical Distribution of SCI for an Urban Authority

The figure shows that an expected worst surface condition is observed for the lower volume
road spectrum when considering Primary collector and below. A higher SCI is observed for
Arterial and Regional road suggesting that these surfaces (predominantly asphalt surfaces)
display a high degree of defects (mostly cracking). Nationwide performance reporting
suggested that asphalt surfaces having significantly higher cracking compared to chip seals.

                                                                                               31
Figure 15: Suggested condition ranges for SCI

                                                               Threshold

                     SCI Condition               Lower (>=)                Upper (
Table 10: Potential additional composite indices

Example of some potential composite indices

Composite Index                    Description

Safety Index                       A safety index that combines road features into an overall assessment of
                                   safety / crash risks. Some examples include KiwiRAP and iRAP (Figure 16)

Structural Index                   An index that describes specific strength features of a road. Some examples are:
                                   • World Bank Modified Structural number concept (SNP)
                                   • Structural indices for Rutting, Flexure and Shear (Henning et al., 2010)

Figure 16: IRAP Star Rating System for Roads (source hhtps://www.irap.org/)

  Road Survey
                                          Data                                                    Investment
                     Road coding                           Processing         Star Ratings
                                       Preparation                                                   Plan
  Road Design

                                       Target: optimise star ratings,
                                    reduce deaths and serious injuries

                                                   Design
                                                   Refined

5.4.3 Future performance areas / measures

The development of performance measures and composite indices is an on-going process due
to ongoing changes and development like data collection and analysis techniques developed.
Furthermore, there are still some known issues associated with some current indices. Table 11
lists some aspects that may require further work on some measures.

Table 11: Future Performance Monitoring Area/ measures

Monitoring Area / Measure          Need / Description                             Development Status

Roughness                          International Roughness Index (IRI) has        We understand the issues, yet
                                   some known limitations as highlighted in       more research is needed to
                                   NZ Transport Agency Research Report 430        develop something better.
                                   (Brown et al., 2010). At this point in time,
                                                                                  Roughness is required as part
                                   it is perhaps sufficient if road controlling
                                                                                  of DIA reporting suite
                                   authorities are aware of the limitations

                                                                                                              33
Monitoring Area / Measure   Need / Description                             Development Status

Pavement preservation /     We use surrogate measures such as rutting      Most Road controlling
sustainability measures     and strength as indicators of whether a        authorities are using
                            network renewal rate is adequate. More         roughness for this, which
                            work is needed in this area                    is the worse measure to
                                                                           use. This is perhaps an area
                                                                           for priority development.
                                                                           Roughness from construction
                                                                           or geological reasons, which
                                                                           does not mean the road
                                                                           needs maintenance. Other
                                                                           measures such as rutting
                                                                           are more useful to indicate
                                                                           pavement deterioration.

Pavement Failure Risk       Most measures we currently use, report on      The initial concept developed
                            performance under prevailing conditions.       - a PhD was completed on
                            Vulnerability to changing traffic loading      developing such a model
                            and/or increasing moisture levels is           (Schlotjes et al., 2014).
                            currently causing difficulties in panning. A   Auckland Transport is trialling
                            failure risk model/index would be useful for   this concept
                            this purpose

Unsealed Roads              Most of the unsealed roads reporting           Refer to NZ Transport Agency
                            aspects are covered in ONRC. Yet some          research report 652 (Henning
                            additional measures would be helpful for       et al., 2018)
                            more effective investment planning into
                            these roads. These include more traceable      More pragmatic ways of
                            customer complaint information, reporting      measuring dust are being
                            on dust emissions and effective monitoring     researched
                            of aggregate source performance and use

Bridges                     There are some strong performance              Refer to RIMS Data Collection
                            frameworks available but are not readily       Framework for Bridges
                            used in NZ. It simply needs more focus

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