This Is AuburnElectronic Theses and Dissertations

A Sensitivity Analysis of the Mobility-Related Benefits of the Alabama Service and Assistance Patrol




Heath, Andrew

Type of Degree



Civil Engineering


The Alabama Service and Assistance Patrol (ASAP) was developed by the Alabama Department of Transportation in an attempt to reduce non-recurring congestion in the Birmingham region of Alabama. This Freeway Service Patrol (FSP) uses roaming vehicles designed to quickly identify and clear traffic incidents upon the freeway network. These patrol vehicles help clear accidents, push stalled vehicles, and directly help customers in need to quickly restore capacity to the network. In performing these actions, ASAP creates mobility-related benefits as a result of reducing incident duration and delay. Calculation of mobility-related benefits is performed with assumptions of a variety of inputs within a traffic simulation process. These input assumptions are dropped through examination of a range of values as opposed to only considering one specific value. This thesis presents a sensitivity analysis of variations of these assumed inputs with respect to the mobility-related benefits generated by the ASAP program. The traffic simulation program CORSIM is applied to vary incident severity, location, time, and duration. Thirty unique scenarios are examined to estimate delay reduction based upon the assistance of an ASAP patrol vehicle. Further analysis is performed to include the effects of average vehicle occupancy and value of travel time upon generated benefits. Finally, the total estimated mobility-related benefits are compared to the corresponding costs. A benefit/cost range of 2.6:1 to 36.5:1 was calculated with a most likely value estimated at 14.4:1. These benefit/cost values indicate that the ASAP program is a cost-effective tool in implementing incident management within the Birmingham freeway network.