On the value of highway travel time information systems

• Published in: Transportation research. Part A, Policy and practice Policy and practice, 2014-12, Vol.70, p.294-310
• Main Author: Soriguera, Francesc
• Format: Article
• Language: English
• Subjects: Costs; Decisions; Departure time selection; Externalities; Highways; Information systems; Reduction; Route choice; Route selection; Travel time uncertainty; Unreliability costs; Utilities
• ISSN: 0965-8564; 1879-2375
• DOI: 10.1016/j.tra.2014.10.005

•Quantification of the value of travel time information in a variety of scenarios.•Extension of the Small’s classic expected utility approach for the trip scheduling.•Consideration of the user and the social value of information.•Consideration of concentration & over-reaction in case of massive dissemination.•Application of the method using empirical data on a Spanish highway. After the widespread deployment of Advanced Traveler Information Systems, there exists an increasing concern about their profitability. The costs of such systems are clear, but the quantification of the benefits still generates debate. This paper analyzes the value of highway travel time information systems. This is achieved by modeling the departure time selection and route choice with and without the guidance of an information system. The behavioral model supporting these choices is grounded on the expected utility theory, where drivers try to maximize the expected value of their perceived utility. The value of information is derived from the reduction of the unreliability costs as a consequence of the wiser decisions made with information. This includes the reduction of travel times, scheduling costs and stress. This modeling approach allows assessing the effects of the precision of the information system in the value of the information. Different scenarios are simulated in a generic but realistic context, using empirical data measured on a highway corridor accessing the city of Barcelona, Spain. Results show that travel time information only has a significant value in three situations: (1) when there is an important scheduled activity at the destination (e.g. morning commute trips), (2) in case of total uncertainty about the conditions of the trip (e.g. sporadic trips), and (3) when more than one route is possible. Information systems with very high precision do not produce better results. However, an acceptable level of precision is completely required, as information systems with very poor precision may even be detrimental. The paper also highlights the difference between the user value and the social value of the information. The value of the information may not benefit only the user. For instance, massive dissemination of travel time information contributes to the reduction of day-to-day travel time variance. This favors all drivers, even those without information. In these situations travel time information has the property that its social benefits exceed private benefits (i