All ETDs from UAB

Advisory Committee Chair

Virginia P Sisiopiku

Advisory Committee Members

Andrew J Sullivan

Christopher Waldron

Document Type


Date of Award


Degree Name by School

Master of Science in Civil Engineering (MSCE) School of Engineering


The Alabama Department of Transportation’s (ALDOTs) Alabama Service Assistance Program (ASAP) helps facilitate the safe and efficient movement of people and goods by providing Safety Service Patrols (SSP) along major interstates in Alabama and utilizing effective incident management strategies to minimize the impacts of freeway incidents. Efficient operation of ASAP improves timely emergency response, increases operational efficiency of the transportation facilities, improves user satisfaction, and results in safety benefits including prevention of secondary crashes. This study focused on developing a new methodology that can determine with greater efficiency when and where ASAP services are needed. The proposed methodology can replace the Incident Factor (IF) method that ALDOT uses currently for deploying the assistance patrol teams which does not consider day, time, and seasonal variations of traffic; traffic composition; or special events. The proposed methodology is demonstrated using a case study in north Alabama. The case study considers a portion of the Alabama interstate network near Huntsville that includes northbound and southbound directions of I-65 and eastbound and westbound directions of I-565. Data on the different segments that made up the study corridors such as the truck percentages, and AADTs were obtained from RITIS and ALDOT. A threshold iv known as Standard Normal Deviate (SND) was calculated for each segment, for days and time periods being considered and used to identify segments that had recurrent and non-recurrent congestion presence. SND values greater than -1.5 indicated recurrent congestion while those less than or equal to -1.5 were categorized as non-recurrent congestion. After identification of congested segments and classification of the congestion type as recurrent or non-recurrent congestion, associated delays were computed for each segment and the dollar value of these delays was calculated. This research presents a method that considers ADT, hourly volumes, traffic composition, day of the week, and cost of congestion in the determination of ASAP service needs. Adoption of the newly developed criteria is expected to improve the efficiency of deployment of ASAP patrol teams and help reduce the impact and cost associated with non-recurrent congestion.

Included in

Engineering Commons



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