TRAFFIC GENERAL DIRECTORATE (DGT) ITS COST-BENEFIT
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TRAFFIC GENERAL DIRECTORATE (DGT) ITS
COST-BENEFIT
Alberto E. Arbaiza Martín
Section Chief. DGT
C/ Josefa Valcarcel – 28, Madrid, 28027, Spain
Tel: (34) 91 301 8337 - Fax (34) 91 301 8540 - e-mail: alberto@dgt.es
Federico C. Fernández Alonso
Unit Head. DGT
C/ Josefa Valcarcel – 28, Madrid, 28027, Spain
Tel: (34) 91 301 8279 - Fax (34) 91 301 8540 - e-mail: federico@dgt.es
SUMMARY
For more than fifteen years, the traffic management Spanish authority (DGT), has installed
a set of Intelligent Transport Systems. A wide rank of signals, VMS equipmets, ramp
metering systems, rerouting strategies, telematic information systems, has gone through the
spanish roads and users. In some cases it has been made socioeconomic studies but never
has been achieved a global vision of the spanish ITS as a whole.
This full sight is the scope of the work that DGT has made along the last 1999
INTRODUCTION
Budget economic and environmental constrictions make it difficult in many cases to absorb
the increasing demand of movility by any making new infrastructures or enhancing the
existing ones.
Traffic managing and information systems, provide a response to this problem by
implementing a wide range of technical as well as human resources. A complex system that
brings together information, analysis, action and anticipation. This actions made this
systems not only a model of public service close to the citizens but also a way of
understanding present and future models in a new landscape of highway traffic.
THE STUDY. BASIC VARIABLE AND EVALUATION
CRITERIA
Contraflow lanes, VMS, SOS systems, High Occupancy Lanes, etc., and now part of the
usual landscape of road, and are familiar to the road user. The question that naturally raises
under the study is the following: is it possible to establish criteria to assess this systems ?, isit feasible to combine a public service with profitability ?, and the most important question: what kind of parameters should be take to obtain reasonable first conclusions ? In a study like the one that has been made there are two main evaluation approaches. It might be study the added value like the push to national industry based on the R&D developed. But in this case it has been focused the socio-economic impact. For this second objective, the multicriteria analysis assess the fulfilment of previous goals fixed by the authority responsible and the cost benefit analysis determine the performance of the implemented measures according to their benefit to society in economic terms. In this study the latter approach has been taken. Any feasibility faces two main problems. The first one is the consideration of non- measeruble effects: how can the effect of the invest been measure ? for instance how can the supresion of family problems and troubles derived from a fatal accident be taken into account ? . The second issue is the monetary value: how can an economic value be assign to measeruble effects ? for instance, how do I calculate the value of people´s time ?, how much does a fatal accident did cost ? Cost-benefit analysis can be expensive and difficult to explain because indirect methods are usually employed to approximate monetary values of public actions. Indirect estimating method are necessary because many public services and benefits have no private sector equivalents. Consequently, no market prices exist for directly estimating benefits. Analysts approximate monetized benefits using various estimating and survey techniques. Human health data, statistical and engineerings model, and laboratory experiments play various roles. Resulting monetary estimates vary widely and are subject to professional disagreement on methods. The study as consider any measurable effect about which there exist a wide range of literature and methodological approaches which should be guaranteed by the EU. Therefore any monetary benefits of ITS on time savings, avoided accidents and reduction on vehicle operation costs has been measured. Other benefits like for example the monetary savings of ITS on terms of pollution have not been taken into account due to the recent publication of the conclusion of the COST 319 on study on the DGT. To develop the cost-benefit analysis models, there were first a monitoring of real cases from the Traffic Management Centre of DGT in Madrid. After an initial examination six different systems were selected on which measurable monetary benefit were calculated. The systems studied: the high occupancy vehicle lane (HOV), the contraflow lanes, the VMS, access extensions to highways, SOS posts, and finally the advance information systems which comprise all the present existing systems for information provision (telephone, radio, TV, internet, SMS, audiotext, videotext, WAP). The helicopter service of the DGT is a special case within traffic managing and information systems, that helps to introduce a singularity of the ITS: the synergy. Helicopters do not have a measurable monetary benefit for evaluation within the former parameters. However, their contribution to the decision to adopt several measures, their proven efficiency as a movil camera, that substitute all non installed cameras in the road network, and their enforcement and preventive work to the road safety, contribute to the all benefits considered by each one of the ITS of the DGT.
Synergy can be added to non measurable benefits and monetary inaccuracies, so that the amount of all the benefits in the study is obviously a part of the total actual benefits. In future research this figure must be modified with the subsequent improvement of the methodology. THE STUDY: METHODOLOGY AND PRESENT SITUATION It is very complicated to establish general common parameters to study ITS as well as the benefits due to them. We can take as an example three pilot cases which are representative of the whole study: the telephone information service 900, the access extensions and the VMS. The telephone information service 900 and time The Traffic General Directorate, as the main body responsible for providing information regarding incidents on the highway network is taking advantage of the possibilities of the new telecommunication and computer technologies in order to reach the citizens. Telephone traffic information service 900 was implemented ten years ago, and in 1999 it received more than 2.250.000 calls. In the economic evaluation of the benefits due to this system, the reason for this calls was studied assigning values according to the type of call. Value of time. Time = money The controversy regarding the value of time arose during the study due to the high dispersion of values found in previous studies (2), (3), (6), (7). In the study it has been used mean values, using the EVA manual (1), (5) as the main reference, crossing with the results of the Movility Household Survey during the weekday in the region of Madrid. The final figure obtained take into account holidays and average vehicle occupation is 1367 pesetas an hour per person (8.2 euros) and 2232 pesetas an hour per vehicle (13.39 euros). Considering the previous 900 telephone service data, and the parameter of the equation time=money, the time savings are 1.264 million pesetas a year (7.58 million euros) Access extensions to highways and vehicle operation costs Vehicle operation costs include costs such fuel, lubricants, tire, etc. This costs are analysed and cuantified one by one using different methodologies. However, the existing literature review has sown a clear tendency to classify this cost in two groups: fuel consumption and others. The agreement of the EVA manual proposal with the second method and the fact
that in the most cases traffic management methods don´t modify the number of kilometre travel but vehicles speed, have lead to the choice in the study of the approach closer to the European evaluation of ITS. The extension of acceleration lanes and slip roads to high capacity highways, using forcing systems and markers, makes it easier for vehicles to enter this type of roads, eliminating vehicles crossing each other, differentiating speeds, and harmonizing access rates. This advance reduces and in most case eliminate disturbances, which creates a worst level of service in the main road. In several studies a time lose of around five to twenty minutes has been estimated from the beginning of the disturbance. The Traffic General Directorate uses this systems in cases where it is foreseen that the demand will reach the capacity of the infrastructure, so unnecessary delays are avoided. A key pilot case is the A-6 motorway Madrid-La Coruña and the access to Villalba. In this point vehicles from the M-601 (Navacerrada), and from N-VI (Puerto de Los Leones) access to motorway. In the evaluation of the measures applied to this case, the estimated vehicle operating cost savings are 300 million pesetas (1.8 million euros). Variable Message Signs (VMS) and Accidents DGT is responsible for the occasional signaling of highways which modify the usual utilization, and uses this systems for more than fifteen years, in order to improve safety and fluently in the infrastructures. VMS have suffer an evolution over the years together with the R&D in the national industry, can offer today response times and signal quality which was not possible assure a time ago. Congestion announcements, location of traffic queues, road narrowing, weather conditions, etc., as a safety elements, which are shown in the VMS. Different field work carried out until the present, allows the reduction percentage and mortality an accident rates to be estimated, and using also information on equipment use and millions of vehicles- kilometres, they provide specific date on safety improvement. Whilst translating this date into monetary terms, a similar value dispersion to data of value of time from existing literature was found (4), (8) (9), and finally the results of the COST action 313, “Socio- economic Cost of Road Accidents” was use. For a citizen of the EU, the following values have been estimated: fatality, 140 million pesetas (840.000 euro), severe injured, 10 million pesetas (60.000 euro), slight injured, 500.000 pesetas (3.000 euro). This values applied to the specific case of the motorway N-I, in the region of Madrid, which has 31 VMS from the M-30 until the Somosierra pass, result in an estimated saving of more than 250 million pesetas a year (1.5 million euros)
Systems and benefits matrix
The three previous samples are part of the following systems and benefit matrix. As
presented before any case under suspicious or have some kind of doubt about its tangibility
and well defined monetary value has been removed.
System / Benefit Time Operational Cost Accident
HOV lane X X
Contraflow lanes X X
VMS X X X
Extended access to X
motorways
S.O.S. system X X
Advanced telematic X
information system
(radio, TV, internet,
teletext, audiotext,
SMS, WAP, 900 tel,
etc.)
CONCLUSIONS
After presenting several specific examples which can summarize the study approach and
the systems-benefit matrix which lets to oversee the scope of the work, it is convenient to
mention the general parameters and road rates that have been used.
The discount rate, which allows to compare the benefits and costs in the present situation
which those expected in the future is fit in 10 %. Traffic increase, taking in account that the
study is related to main highway in big city accesses was estimated around 7 %. The
growth in vehicle operating costs has been assumed to be constant in real terms over time
since this cost is usually detected and immediately corrected by manufacturers and
suppliers. Finally the growth of the value of time have been fixed in 1.85 %, half of the
foreseen economic growth rate.
The study carried out for DGT ITS has been made in accordance with the wishes of the
DGT to continue the task of using new management technology, and carrying out the clear
will of the public services. As a result of this work it has been proved that our ITS used in
the traffic control centres which are those utilized for the study or those of other
management centres, are amortized in a short period of time, similar to other countries, and
which in Spain does not exceed 5 years.The study guarantees the appropriateness from the socio-economic point of view of the
implementation of ITS for traffic management. But it is also an open introspective view
apart from statistics and data, a current proposal to understand resources and optimize the
service. It is in short an essential reference for current and future challenge for traffic.
References
(1) Program DRIVE. Proyect V1036. CEC. “EVA Manual. Evaluation Process for Road
Transportation Informatics”. 1991
(2) Servicio de Planeamiento. Ministerio de Fomento. “Recomendaciones para la
evaluación económica, Coste-Benefico de estudios y proyectos de carreteras”. Spain.
1996
(3) Cañada, J. / Olivares, A. / Pinilla, J. / Revista de Estudios de Construcción Transportes
y Comunicaciones. Nº 76. Ministerio de Fomento. Spain. 1997
(4) CEC. COST 313. “Coste socioeconomico de los accidentes de carretera”. 1994
(5) COBA Manual. “Design Manual for roads and bridges. Volume 13. UK. 1996
(6) U.S. Department of Transportation. FHA. “Review of ITS Benefits: emerging
sucesses”. USA. 1996
(7) Frybourg M. / Orselli, J . “Evaluation monétaire de l´informations sur les PMV de
Sirius Est”. France. 1996
(8) Forschungsgesellschaft für Strassen und Verkherswesen (Dr. Meewes). “Empfehlungen
für Wirtschaftlichkeitsuntersuchungen am Strassen (EWS)”. Deutschland. 1997
(9) Public Works Research Institute. Ministry of Construction. “AHS Cost-Benefit
Analysis Manual”. Japan. 1997You can also read
