Following a major earthquake, one of Caltrans' most critical tasks is to assess the condition of all potentially impacted bridges and roadway corridors in the state highway system. Timely response is important to ensure public safety, guide emergency vehicle traffic, and re-establish critical lifeline routes. In the past, bridge inspection teams had difficulties setting priorities immediately following an earthquake, because they lacked precise information about where the worst shaking and, most likely, the greatest damage had occurred. In 2005 Caltrans initiated a contract with the United States Geological Survey (USGS) to develop and implement a Caltrans-specific version of their ShakeCast system, a post-event software analysis tool that was anticipated to change the way Caltrans responds following a major earthquake. ShakeCast is a web-based application that automatically retrieves measured earthquake shaking data, analyzes it against individual bridge performance characteristics, and generates inspection prioritization emails and other web-based products for emergency responders within minutes of an event. Benefits have already been realized over the course of the test deployment phase. The ShakeCast system has proved to be a valuable tool for post-earthquake response for Caltrans during real events as well as for scenario planning exercises.