Odile Andan

Exploring the Process of Driver Route Choice for Regional Trips

The main focus of this paper is to explore the possibility to isolate specific groups of car drivers with regard to their flexibility (their propensity to change their route), and, if such groups were identified, to find out under what conditions they decided to change route and which parameters explain behavioral differences between such groups. The design of the survey method used for the study is described; and the methodology used to analyze the data is explained. The results obtained are presented for two scenarios: impact of adverse weather conditions and impact of rerouting.

The accessibility of big towns in France

Abstract Around a town, the transportation mesh has a very important significance. If the means of access (roads, railroads) are numerous and well layed out, it indicates that accessibility is good; but a wonderful network of diverse arteries may be poorly used which means that the power of attraction of the city is poor. Our fundamental hypothesis is that the design of the network and the intensity of circulation give the best picture of the regional influence of a town; it expresses exactly the systemic relations between the center and its environment. We decided to study this type of relationship around the main French towns (with more than 100,000 inh. in 1968). In the present paper, we are using the ten for which the work has been completed. We used the data given for railways, roads and bus transportation. Two methods were experimented with. The first one is classical and mainly cartographic and descriptive: results are shown by maps for two examples and comparative indices. The second one is a model of a stochastic type. It takes into account the number of inhabitants, their wealth, the number of their cars and the distances which separate the different centres. The results seem to correspond pretty well with the direct field knowledge. It was possible to obtain spheres of influence and the relative weight of each centre in the overall pattern of regional relations. The model has been tested thus far only for roads.

The Simulation of Behaviour in a Nonexperienced Future

Is it possible to simulate in a realistic manner behavioural reactions to a nonexperienced and a priori nonaccepted travel situation such as urban road pricing? We base our methodological answer on a series of gaming-simulation interviews of a small group of drivers. On the basis of one of their previous driving days, respondents had to adapt their behaviour to traffic congestion and driving bans and then, after the introduction of a new public transport supply, to scenarios of pay parking and finally of urban road pricing. As congestion is a phenomenon which the respondents know well and have often lived through, even if it has never been too serious in their own experience, the analysis of how the simulation operates suggests that this method of simulation could be relevant. This is how the application of this method is made possible for urban road pricing scenarios, which have not been experienced, nor initially accepted. The pertinence of the adaptations carried out and the implication of the respondents do not contradict the ability of this simulation method to elicit reactions. The stated adaptations--search for space and time modifications, resistance to congestion, apparent absence of costs calculation and partial transfer to public transport--suggest particular behavioural decision processes which need further validation. Methodological issues are also discussed, which help to point at the limits of application of this method. Apart from helping the construction of questionnaires for conventional stated preferences surveys, the main advantages are the exploration of choice processes, rather than elaborating the actual future adaptations themselves, and the working out of behavioural hypotheses.