Nonlinear Disutility of Travel Delay: Implications for Traffic Diversion Benefit and Strategy

Most travelers tend to be tolerant of or oblivious to short travel delay whether it is expected (a result of recurring congestion) or unexpected (a result of nonrecurring congestion). In contrast, long travel delay is disproportionately burdensome, especially if it is unexpected. Thus, the disutility of travel delay, as subjectively assessed by the typical traveler, is nonlinear. The social benefit of traffic diversion for congestion reduction has traditionally been determined from calculations based on a linear disutility of delay. If, instead, a nonlinear disutility curve is used, the benefit might be substantially higher. In addition, graphical analyses taking nonlinear disutility into account suggest new traffic management strategies for diversion from incidents. A need for research to better determine the distribution of individual travel delay is indicated.