Reliability of travel time has become an important aspect of transport systems. The economic value of travel time uncertainty is substantial, both for persons and freight transport. An empirical research among truck drivers shows that risks attached to unreliable travel times play an important role in their route choices. A choice between an on average smaller travel time and an on average longer but more reliable travel time usually falls on the latter one. The relative valuation of uncertainty turns out to be quite high in another research as well. A reduction of uncertainty (in this research expressed as the value of the 90th percentile travel time) by one minute is valued twice as much as the reduction of one minute regular travel time. Furthermore, the economic value of travel time uncertainty is large. The current policy to reduce travel time uncertainty is therefore a good one. (Author/publisher)
Abstract