This paper investigates the traffic safety impacts of mobility management, which consists of various strategies that increase transportation system efficiency by changing travel behavior. Safety impacts depend on types of travel changes that occur. Because most crashes involve multiple vehicles, reducing vehicle mileage reduces risk both to motorists who drive less and to other road users. Mileage reductions tend to provide a proportionately larger reduction in total crash costs. Empirical evidence indicates that each percentage reduction in total vehicle mileage in an area reduces total crash costs by 1.0% to 1.4%. The safety impacts of mode shifting depends on the relative risks of each mode. Shifting vehicle travel from congested roads to less-congested conditions tends to reduce crashes but increases crash severity due to higher vehicle speeds. Strategies that reduce traffic speeds provide significant safety benefits. Conventional traffic risk analysis often understates the full safety benefits of mobility management. This analysis suggests that mobility management can be a cost effective traffic safety strategy, and increased safety is one of the largest potential benefits of mobility management. (Author/publisher)
Abstract