Estimating the information value for travelling time on a toll motorway

This paper analyzes the value of highway travel time information systems. This is achieved by using notions of expected utility theory to develop a departure time selection and route choice model. The model assumes that every driver has a level of accepted lateness for his trip and some perceived knowledge of the travel times on the route. Only these two inputs support his decisions. The results of the model are used to compute the unreliability costs of the trip (i.e. scheduling costs and stress) and to obtain the benefits of real-time information systems. Results show that travel time information only has a significant value when there is an important scheduled activity at destination (e.g. morning commute trips), in case of total uncertainty about the conditions of the trip (e.g. sporadic trips), or when more than one route is possible. Systems with very high accuracy are not in better terms. The paper also highlights that the value of the information may not benefit only the user, but all drivers, even those without information. This social benefit of information reduces the marginal benefit of being informed (i.e. the user benefit). While this reduction of the social costs can be a policy objective, there is no reason to expect individuals to pay out-of-pocket for travel time information, beyond the user value.