01518177

Component

This study seeks to develop an efficient approach for estimating clearance time for evacuation operations, which will be used to assess evacuation risk. The approach needs to be computationally efficient for use in real-time evacuation operations, while being capable of approximating traffic flow dynamics reasonably. An approach based on the framework of dynamic network flow problems (DNFPs) which serve as intermediate tools between static and dynamic traffic routing approaches to leverage the trade-offs between traffic realism approximation and computational efficiency is approached. By analyzing the characteristics of evacuation networks, a dynamic routing policy labeled the demand-priority routing is proposed. It defines the priority of demand in using roadway capacity for evacuation based on the associated spatial risk due to the disaster; the demand with higher priority is recommended for evacuation earlier. When combined with the application of a super sink, the problem can be transformed into sequential single-origin single-destination dynamic routing problems (s-t DRPs). The sequential routing scheme can avoid an iterative search process, thereby allowing computational efficiency for real-time evacuation operations. A solution method for finding the quickest flow in an s-t DRP is developed. It circumvents the need for computation over time-expanded networks used in most existing DNFP solution algorithms, and can be implemented in a continuous-time context. The complexity analysis shows the superiority of the proposed method in terms of more efficiently finding the quickest flow. Numerical experiments illustrate that the proposed approach can address the aforementioned needs and trade-offs related to estimating the clearance times.

This paper was sponsored by TRB committee ANB80T Emergency Evacuation.

01503729

14-2730

English

19p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; References; Tables

Advanced driver information systems; Evacuation; Time; Traffic flow rate

Computational efficiency; Road networks

Data and Information Technology; Highways; Operations and Traffic Management; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2014 Paper #14-2730

TRIS, TRB, ATRI

Jan 27 2014 2:56PM