Reestimation of time values and determinants of road route choice — DGITM

Les values of time And the Malus of discomfort or reliability are central variables in modeling travel choices. They determine the sensitivity of users to travel times, costs, costs, congestion or uncertainties — and therefore condition the accuracy of tools for simulating and evaluating transport policies.

However, the reference values used in France were more than ten years old and no longer reflected the major transformations that have taken place since then: generalization of digital technology, diversification of mobility, evolution of infrastructures and increased expectations in terms of reliability.

For the DGITM, Explain has designed and managed a novel scientific approach, combining qualitative methods, large-scale surveys and advanced econometric analyses:

1. Qualitative and exploratory approach
   • Animation of Focus groups in order to identify the subjective determinants of itinerary choice and their variations according to profiles (age, use, location).
   • Analysis of social representations of comfort, reliability and stress related to travel.
2. Declared preference surveys (SP)
   • Design and administration of a National questionnaire (5,000 respondents) simulating alternative route choices, calibrated according to international standards.
3. Exploitation of revealed preference data (RP)
   • Mobilization of more than 15 years of CORDON surveys and data FCD (Floating Car Data) covering the entire French network, a first on this scale.
4. Econometric estimation and scientific validation
   • Development of discrete and stochastic choice models for light and heavy vehicles.
   • Validation by comparison with results from academic and international literature.

Explain was based on a mixed team of researchers and practitioners, in partnership with Matthieu de Lapparent and Nicolas Coulombel, guaranteeing the methodological robustness and scientific credibility of the results.

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The mission aims to provide the French State with a updated base of behavioral parameters, essential for modeling and evaluating public policies.
Specific objectives:

• Reestimate the time values and discomfort coefficients for different profiles and contexts;
• Integrate massive and real data to the analysis of mobility behavior;
• Provide a common scientific base for traffic studies, socio-economic assessment and national planning.

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This mission offers the DGITM a updated reference tool, guaranteeing the consistency and reliability of public evaluations.
The results will strengthen the accuracy of transport models, the transparency of socio-economic calculations and the robustness of investment decisions.
Explain's work also contributes to the dissemination of a scientific culture of mobility behavior within administrations and design offices.

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This project illustrates the ability ofExplain To drive complex behavioral studies at the interface between academic research and public decision-making.By reevaluating the values of time And the determinants of itinerary choice, Explain is participating in the modernization of simulation and evaluation tools which structure French transport policies.