Cost-of-Delay Studies for Freeway Closures Caused by Northridge Earthquake

Abstract

On January 17, 1994, the Northridge earthquake in California destroyed structures on four important freeways in the Los Angeles basin. Closure to travel on these damaged freeways had significant local, regional, and statewide impacts for general travel, as well as for commuter and commodities movement. Initial research indicated that the four route closures on the I-5, I-10, CA-14, and CA-118 freeways had significant ramifications on the local and state economies on the order of millions of dollars per day. With this in mind, the state of California set up high-incentive reconstruction contracts that paid private contractors significant bonuses for early reopenings of damaged routes. Further research conducted as part of the comprehensive transportation recovery evaluation justified those bonus clauses and indicated that the quantifiable (direct) transportation-related costs associated with the travel disruption and delay on the four damaged routes combined in the Los Angeles basin exceeded $1.6 million per day. The methodology used to calculate the cost-of-delay estimates for each route was based on detailed counts, surveys, and travel time (delay) data collected during the reconstruction periods, as well as computer simulation and adopted costing techniques. The geographic and systemwide extent of the impacts of closures was simulated through travel demand assignments on EMME/2 modeled highway networks that were modified to represent the earthquake-damaged system. When the economic analysis is broadened to include indirect costs associated with trip elimination, areawide disruption to shipping, or loss of jobs caused by the earthquake emergency, a much higher transportation-related cost to the California economy can be calculated.