California Department of Transportation

Caltrans REDARS Demonstration Project

What is REDARS

REDARS (Risks from Earthquake Damage to Roadway Systems) is an advanced seismic risk analysis software package that will enable Caltrans to improve its ability to plan for and respond to earthquake emergencies. REDARS will allow transportation decision makers to evaluate and prioritize how various seismic-risk-reduction strategies will improve post-earthquake traffic flows and reduce associated losses.

Earthquake damage to highway systems can severely disrupt traffic flows and operations at the network level, thus leading to widespread economic impacts and effects on post-earthquake emergency response and recovery. REDARS is a unique methodology that estimates earthquake effects on system-wide traffic flows through the integration of geosciences, earthquake engineering and transportation engineering technologies. It is the most advanced and developed SRA methodology currently available. REDARS has been under development by Federal Highway Administration (FHWA) and the Multi-Disciplinary Center for Earthquake Engineering Research (MCEER) as a future public-domain software package since 1993. It was successfully applied to the Memphis, TN highway network, a location that is vulnerable to a repeat of the 1812 New Madrid zone earthquakes. The success of the Memphis study has provided the confidence necessary to move toward application to the significantly more challenging California environment where the earthquake sources are more pervasive, the highway network is more extensive, and the economic consequences are more profound.

Research Objective

This project is aimed at transferring technical expertise from the developer community (at FHWA and MCEER) to Caltrans. We have identified an evaluation "testbed" network in Northern California that contains all of the essential elements needed to exercise the major components of the REDARS methodology. Caltrans research staff, working under the guidance of the contractor and in close coordination with end users from both Caltrans and outside agencies, will use the testbed network to develop expertise, implement improvements to the methodology, investigate key sensitivities and uncertainties, and develop recommendations regarding its applicability for general use in California.


  • Federal Highway Administration (FHWA)
  • Multidisciplinary Center for Earthquake Engineering Research (MCEER)
  • Federal Emergency Management Agency (FEMA)
  • Office of Emergency Services (OES)
  • U.S. Department of Transportation (USDOT)
  • Pacific Earthquake Engineering Research (PEER).


For more information about this research project:

Mandy Chu
Project Manager

REDARS Test-Bed Network