The Specification of the Planning Systems; Report of the 1993 Questionnaire Survey

This report describes a survey carried out as part of a research project undeaaken hy the Institute for Transport Studies and the School of Computer Studies at the University of Leeds, funded by the Science and Engineering Research Council. The project was concerned with the specification of trip planning systems, which are systems which provide information to travellers and potential travellers ahout all aspects of their journey, but in this case principally route and timetable information for public transport users and route information for car travellers before the journey is made.

Previous evidence had suggested that travellers may make sub-optimal travel decisions, meaning that they may make longer, slower or more expensive journeys than necessary because of imperfect information. Other parts of the project addressed sub-optimality in the choice of mode and time of travel but a main objective of the survey described in this report was to examine sub-optimality of route choice separately for journeys with which respondents were familiar and journeys with which they were unfamiliar. Other objectives were concerned with the travel information currently used, or desired by, the respondents, who were randomly-selected travellers from the West Yorkshire town of Mirfield.

Maps were widely used by car drivers - about one in five used them for familiar trips and ahout three quarters used them for unfamiliar trips. For public transport trips, timetables were used hy about half of the travellers making familiar trips and 95 per cent making unfamiliar trips. Information on delays would have been welcomed by both private and puhlic transport travellers: nearly three-quarters of familiar and unfamiliar car trips would have liked congestion information as would a significant minority of bus users. Most of all, public transport-users would have welcomed information on service delays and cancellations. It would seem that real-time information on delays would be a key feature of a successful trip planning system.

The sub-optimality for car journeys averaged at 2.6 minutes per trip for familiar trips and 6 minutes per trip for unfamiliar trips. Sub-optimality was directly related to trip distance for familiar trips hut not for unfamiliar trips. This indicates a modest hut significant reduction in car journey times could be brought about by trip planning systems. Public transport trip sample sizes were too small to permit reliable estimates to be made of their sub-optimality.