Assessing Cost Efficacy of the Caltrans Phase I and Phase II Bridge Retrofit Program

In the last 40 years, earthquakes in California have caused freeway bridge collapses in urban areas resulting in considerable economic disruption and fatalities. Following the 1989 Loma Prieta earthquake, where 43 people died as the result of a single bridge failure, the State of California embarked on a significant bridge retrofitting program to help curb future impacts. Under the Multihazard Mitigation Council (MMC) project, the cost efficacy of these efforts was assessed using REDARS (Risk from Earthquake Damage to Road Systems), a software tool that estimates damage to bridges and analyzes disruption experienced road networks after an earthquake event. The analysis also considered secondary economic impacts, which in many cases are far greater than the direct impacts, resulting in a benefit cost ratio of 3 to 1. This paper presents the results of this analysis, and suggests methods of preserving this early 2000s era computational framework using cloud-based technologies.