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Join the tailback, or get round it?
30 June 2009
NWO (Netherlands Organization for Scientific Research)
It's the same dilemma every morning: do you take your usual route with its frequent tailbacks, or try to get to work faster by going cross-country? And do you listen to the advice from the traffic information service, or work it out yourself? Dutch researcher Enide Bogers investigated what we actually learn from our own experience and what we do with all of the good advice we receive. Although we appear to be stubborn creatures of habit, good traffic information makes us a bit more adventurous.
Traffic expert Bogers investigated the extent to which people make their decisions on the basis of the information they receive. She found that the subjects who received a lot of traffic information en route opted more often for a route that was unreliable but fast. The subjects who received no information, on the other hand, opted more often for a reliable but slow route. So it cannot do any harm to switch on the car radio in the morning. The more traffic information the drivers in the study received, the more time they saved.
In her study, Bogers asked 2500 subjects to choose one of three possible routes on forty separate occasions. The first route was usually very fast (three days out of four) but sometimes extremely slow. The second route was very reliable but slow. On the third route, the journey time was completely random within certain limits. The provision of traffic information appeared to increase the attractiveness of unreliable routes (one and three).
Creatures of habit
However, Bogers examined not only the influence of the information provided, but also what the subjects learned from their experience during the experiment. Strikingly, the role of habitual behaviour became greater and greater. Even those who received a lot of information allowed their decisions, as time went by, to be increasingly determined by habit than by other things such as the information provided or their own acquired expectation in terms of journey time. Indeed, it seems that a poor journey time on a habitual route is rated better than a poor journey time on an alternative route. Many drivers are apparently not willing to accept that their favoured route may not always be the best one.
In addition, those travelling without traffic information based their expected journey time predominantly on their most recent experience. Those travelling with traffic information, however, took a much wider range of experiences into account in calculating their expected journey time.
Despite these ingrained habits, the use of traffic information still appears to hold many possibilities. Not only can it reduce individual journey times, but it can also ensure that routes which are normally seen as unreliable are used more often. Traffic information can therefore cut vehicle hours, resulting in less traffic and less environmental pollution.
Enide Bogers' research is part of the AMICI programme (Advanced Multi-agent Information and Control for Integrated multi-class traffic networks), part of the NWO stimulation programme Traffic and Transport. The latter aims to develop and disseminate integrated knowledge geared to innovative and balanced traffic and transport solutions. This knowledge should lead to high-quality applied research in companies and government organisations.