Analysis and design of freeway incident response systems: Chyi Lang Lu, Parsons, Broinckerhoff, Quade and Douglas, 25 Maiden Lane, San Francisco, CA 94108 (dissertation in the Department of Civil Engineering, University of California, Berkeley)

Abstract

Described in this paper is the development of a two-phase procedure for the optimal design of nine specific types of a freeway incident response system. As a basis for analysis, individual system components were classified into three groups according to their functions and design variables: (a) detection, (b) service, and (c) detection and service. Mean response time was selected as the measure of system effectiveness. In the first phase, steps leading toward the optimal disposition of a given number of detection or service units or both in the service area were developed for each component group. The relationship between mean response time and component design variables was first derived. Mathematical programming techniques were then used to determine the optimal component design that minimizes the mean response time. The optimal allocation of a given resource (e.g., annual budget) among competing components of a total system was determined in the second phase by using the results from the first phase. Based on component interactions, the relationship between mean system response time and the response times of individual components was formulated as the objective function of a resource allocation problem. For a given resoruce, the optimal component integration for a specific type of system was generated by solving this problem. Potential applications of this two-phase procedure in system design and in evaluating alternative system types were demonstrated by numerical examples. Although analysis results and conclusions were limited to the specific types of systems and the hypothetical input data considered in this study, the methodology is general and can be applied to the planning and design of other types of systems not considered here. /Author/