The effects of freeway management systems and motorist assistance patrols on the frequency of reported motor vehicle crashes

Freeway Management Systems (FMSs) and Motorist Assistance Patrols (MAPs) are two policy tools used by public officials to improve the efficiency of motor vehicle travel on urban highways. Developed during the 1960s, these tools are becoming a popular approach to reducing traffic congestion in major urban areas, especially compared to more expensive and politically challenging alternatives like building additional highway capacity or imposing road pricing. Since the passage of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA), with its emphasis on making existing highway facilities more efficient, more than 30 Freeway Management Systems and more than 30 Motorist Assistance Patrols have been implemented in cities across the US. This represents approximately two-thirds of all such programs now in existence.; Although FMSs and MAPs were developed primarily to reduce traffic congestion, they are widely believed to improve traffic safety as well. However, despite the fact that more than 100 of these programs exist in the US today (more than 50 of each kind), surprisingly little is known about the safety benefits of either FMSs or MAPs in practice. To date, public officials have little knowledge of the magnitude of the safety effects of these programs, let alone the dollar value of the resulting safety benefits.; This thesis provides strong empirical evidence of the safety effects of these two tools through two case-study assessments—one in Phoenix, Arizona and the other in the Twin Cities area, St. Paul/Minneapolis, Minnesota.; The thesis supports three general findings: (1) Both FMSs and MAPs significantly reduce multivehicle, low-severity crashes. (2) Investments in both policy tools are justified by their resulting safety benefits alone. (3) The safety benefits of the programs are approximately the same order of magnitude as the congestion reduction benefits.; Taken together, these results both confirm the widely held belief that FMSs and MAPs improve highway safety and demonstrate that the policy tools represent sound investments of taxpayer dollars, at least in urban areas similar to Phoenix and the Twin Cities.