Weighting Waiting: Evaluating the Perception of In-Vehicle Travel Time Under Moving and Stopped Conditions

This paper describes experiments comparing traditional computer administered stated preference with virtual experience stated preference to ascertain how people value stopped delay compared with stop-and- go or freeflow traffic. The virtual experience stated preference experiments were conducted using a wrap around driving simulator. The two methods produced two different results, with the traditional computer assisted stated preference suggesting that ramp delay is 1.6 Ð 1.7 times more onerous than freeway time, while the driving simulator based virtual experience stated preference suggested that freeway delay is more onerous than ramp delay. Several reasons are hypothesized to explain the differences, including recency, simultaneous versus sequential comparison, awareness of public opinion, the intensity of the stop-and-go traffic, and the fact that driving in the real-world is a goal directed activity. However without further research, which, if any, of these will eventually prove to be the reason is unclear. What is clear is that a comparison of the computer administered stated preference with virtual experience stated preference produces different results, even though both procedures strive to find the same answers in nominally identical sets of conditions. Because people experience the world subjectively, and make decisions based on those subjective experiences, future research should be aimed at better understanding the differences between these subjective methodologies.