Report numberRA-MOW-2011-001
TitleTime valuation in traffic.
SubtitleCongestion costs, value of time & lost vehicle hours.
AuthorsKoen Van Raemdonck
Cathy Macharis
Published byPolicy Research Centre for Mobility and Public Works, track Traffic Safety 2007-2011
Number of pages35
Document languageEnglish
Partner(s)Vrije Universiteit Brussel
Work packageOther: Evaluation techniques

In this report a method to calculate the congestion costs as a result of a road accident is presented. First, all the costs associated with an accident are discussed. On the one hand there are the injury-related costs like the medical costs, the costs because of production losses and the intangible costs. On the other hand there are the accident-related costs, being the tangible or material costs, the handling costs and the congestion costs.


With these last costs the lost vehicle hours seem to play an important role. On the other hand, the value of travel time is of great importance in the calculation of the congestion costs. This is why the value of travel time is studied in more detail. The problem of the variation in travel time valuation is raised, as well as the differences in the valuation of time of freight transport, commuting, business-related traffic and other traffic. These differences manifest themselves in the fact that freight transport and business-related traffic (traffic during paid working hours) have a much higher value of travel time compared to commuting or other traffic such as traffic for shopping or recreation.


Thereafter, the lost vehicle hours are studied in more detail. It appeared that for Belgium or Flanders a fully redundant system with closed road segments and double induction loops to measure vehicle speeds and intensities does not yet exists (the extension of the current network to such a network however, is planned for 2012). Because of this, the data is not always as reliable as needed, which is why the different methods for calculating the lost vehicle hours are studied in a literature review. On the basis of this literature study, a new framework was derived, so that in further research, after collecting the necessary data, a more reliable calculation of the lost vehicle hours can be performed.


Finally, the costs of congestion are being discussed. Congestion costs are divided into costs by alternative behavior, costs incurred by the unreliability of travel times and costs for the average extra travel time. Among alternative behavior we mean leaving at a different time, travelling with a different transport mode, using a different route, or even completely renouncing from the journey. Unreliability of travel time is present when the predictability of travel time is small and the variation in travel time is high. The costs for extra travel time include all costs by time losses incurred by road users summed over a certain time horizon, expressed in money. They only represent the waste of time while underway and do not cover the total economic impact of congestion and delays, nor the maximal benefits that could be obtained by solving a traffic jam. These costs for the average extra travel time are calculated, followed by a thorough discussion on the restrictions of this calculation and the used data. Conclusion finalizes the report.

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The Policy Research Centre for Traffic Safety carries out policy relevant scientific research under the authority of the Flemish Government. The Centre is the result of a

cooperation between Hasselt University, KU Leuven and VITO, the Flemish Institute for Technological Research.


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