COMPUTER-AIDED DESIGN AS APPLIED TO TRANSIT SYSTEM EMERGENCY CONTINGENCY PLANNING

Abstract As shown by the experiences gained in recent energy crises, transit agencies should prepare emergency contingency plans to deal with possible rapid and sharp increases in the demand for transit service. In this paper, contingency plans are developed for two suburban areas, Bellevue and Federal Way, in the Seattle, Washington metropolitan area. Bus transit system designs are developed for three emergency levels: 100, 75 and 50% of the work trips to be carried by buses. Altogether, 10 plans are developed. Six assume no vehicle availability constraints, and four assume only existing Metro and school buses are available. Results indicate that bus vehicle requirements for the 100 and 75% levels far exceed likely vehicle availability levels while the 50% level could be handled with currently available vehicles (Metro fleet combined with school buses). This design work was accomplished rapidly and effectively with an interactive graphic computer program called the Transit Network Optimization Program (TNOP). It would be impossible to do a similar study using conventional transit planning techniques.