Olave-Cruz Isac, Stéphan Maïté, Volle Alexandre, Zhu Dianzhuo - Does Carpooling Reduce Carbon Emissions? The Effect of Environmental Policies in France
Environmental and Resources Economics, Vol. 80, January 2025, pages 1111-1144.
Road transportation is among the most carbon-intensive sectors in the economy, underscoring the urgent need for strategies to meet climate objectives. Carpooling has emerged as a promising solution for carbon mitigation. However, by making car travel more attractive, carpooling may lead to ambiguous environmental outcomes. This study evaluates carpooling's potential to mitigate carbon emissions and explores various strategies to enhance its environmental benefits. A key focus of this research is the vehicle occupancy rate, which we define as robust metric for assessing carpooling's carbon mitigation potential. This metric is reliable as it accounts for travelers' preferences for alternative transport modes. We also analyze how policies that impact monetary trip costs influence carpooling adoption. Using a unique database from France's leading carpooling platform, we show that increasing monetary trip costs through carbon pricing boosts both carpooling demand and supply, while improving occupancy rates. Furthermore, we find that novice users are particularly sensitive to fluctuations in monetary trip costs. In addition to this policy, we explore the effect of encouraging drivers to transition into passengers. Our results suggest that this strategy holds significant potential for further reducing carbon emissions. The insight from this study are crucial for policymakers seeking to design more effective strategies for reducing vehicle emissions and achieving climate targets.
Keywords: Carbon Mitigation; Carpooling; Carbon Pricing; Climate Policies
Blayac Thierry, Stéphan Maïté - Travel information Provision and Commuter Behavior Changes: Evidence from a French Metropolis
Case Studies on Transport Policy, Vol. 10 (2), June 2022, pages 1132-1143.
This study aimed at assessing the role of travel information on behavioral changes in daily mobility in the metropolis of Montpellier in France. We focused on commuter behavior using data collected through an online survey on mobility behavior during the summer of 2015. We found that while 73% of commuters respondents use travel information sources, only 31% of them declared any mobility behavior chnage. This study explores the impact of specific factors such as socio-demographic variables (e.g., age and gender) and transportation habits (e.g., public transportation pass, travel time, and safety margin). As an operational measure of the prudent behavior, safety margin highlights the threshold effect of travel information provision on behavioral changes. Indeed, three commuter profiles can be distinguished according to their prudence levels: chronically non-prudent, reasonably prudent, and excessively prudent. Finally, the study highlights that travel information provision alone may not be enough to induce a shift in behavioral changes among commuters toward more environment-friendly modes of transportation.
Keywords: Travel information; Mobility Behavior Changes; Commuter; Transportation Habits; Sustainable Urban mobility.
Blayac Thierry, Stéphan Maïté (2021) - Are retrospective rail punctuality indicators useful? Evidence from users perceptions.
Transportation Research part A, Vol. 146, March 2021, pages 193-213.
This paper analyzes the perceptions of individuals on retrospective rail punctuality indicators to determine the most useful indicator according to socio-demographic characteristics, regular trip behavior variables, and railways transportation habits variables. In choice situations, individuals must choose between four punctuality indicators and an out option. Common punctuality indicators have been selected among those proposed by the authority for quality of service in transport, as well as a new punctuality indicator from the financial literature: Delay-at-Risk. Thus, via an online survey and econometric modeling, we show that respondents appreciate the usefulness of punctuality indicators for planning their long-distance rail trips. The uselfulness is reinforced by the fact that respondents employ several modes for regular trips and frequent train users. Moreover, they have already experienced missed appointments or connections. The risk attitude and prudence of respondents also play an important role but not totally in the expected direction. Lastly, Delay-at-Risk, although unknown and more complex in its formulation, exhibits some characteristics that are appreciated by users.
Keywords: Reliability; User perceptions; Rail transportation; Retrospective punctuality indicators; Information.
Blayac Thierry, Reymond Mathias, Stéphan Maïté (2020) - Can digital technologies induce behavioral changes in transportation habits? Evidence based on User Experiencce with the SmartMoov Application.
Revue d'économie industrielle, numéro spécial Economie numérique, Vol, 172, 4ème trimestre 2020, pages 179-215.
This study aims to assess behavioral changes in transportation habits induced by real-time and multimodal information provided by a mobile application, SmartMoov. The users of SmartMoov application (beta-testers) are registered on a voluntary basis. After three months of testing the mobile application in a living lab in Montpellier Méditerranée Métropole, we analyze beta-testers' feelings and changes in transportation behavior. Although the beta-testers represented a unique population segment, econometric modelling shows that they are sensitive to the information provided by the application and use it to modify their mobility behavior. They are more likely to change their route and departure time than transportation mode. While the average travel time and the safety margin affect overall mobility changes (i.e., mode, route, and departure time), there are additional factors that influence changes in the route and departure time. Specifically, a gender effect is documented in the context of departure time choice.
Keywords: Mobile application; Behavioral changes; Transportation habits; Living lab; Advanced traveler information system.
Beaud Mickaël, Blayac Thierry, Stéphan Maïté (2016) - The impact of travel time variability and travelers'risk attitudes on the values of time and reliability
Transportation Research Part B: Methodological, Vol. 93, November 2016, pages 207-224.
In this paper, we derive implementable measures of travelers' willingness to pay to save travel time (VOT) and to improve the reliability (VOR) of a given trip. We set out a simple microeconomic model of transport mode choice in which each trip is fully characterized by its price and the statistical distribution of its random travel time, assuming that travelers have expected utility preferences over the latter. We then explore how the VOT and VOR affected by the statistical distribution of travel time and by travelers' preferences towards travel time variability.
Keywords: Value of travel time savings; Value of travel time reliability; Risk attitudes; Reliability proneness; Prudence; Cost benefit analysis of transport infrastructure projects.
Beaud Mickaël, Blayac Thierry, Stéphan Maïté (2012) - Value of Travel Time Reliability: Two Alternative Measures
Procedia-Social and Behavioral Sciences, Vol. 54, 4 October 2012, pages 349-356.
This paper deals with the estimation of the willingness to pay for travel time reliability (VOR). We report on a stated preferences survey and we provide an econometric treatment of the data using a conditional logit model. Estimations are made according to two alternative approaches: The first uses a mean-variance approach and the second uses specific coefficients for the preferences function. Although the two approaches are significantly different, both yield quite similar estimations for the VOR.
Keywords: Value of Reliability; Stated preferences; Discrete choice model.