Transportation system disruption due to a disaster results in “ripple effects” throughout the entire transportation system of a metropolitan region.Many researchers have focused on the economic costs of transportation system disruptions in transportation-related industries,specifically within commerce and logistics,in the assessment of the regional economic costs.However,the foundation of an assessment of the regional economic costs of a disaster needs to include the evaluation of consumer surplus in addition to the direct cost for reconstruction of the regional transportation system.The objective of this study is to propose a method to estimate the regional consumer surplus based on indirect economic costs of a disaster on intermodal transportation systems in the context of diverting vehicles and trains.The computational methods used to assess the regional indirect economic costs sustained by the highway and railroad system can utilize readily available state departments of transportation(DOTs)and metropolitan planning organizations(MPOs) traffic models allowing prioritization of regional recovery plans after a disaster and strengthening of infrastructure before a disaster.Hurricane Katrina is one of the most devastating hurricanes in the history of the United States.Due to the significance of Hurricane Katrina,a case study is presented to evaluate consumer surplus in the Gulf Coast Region of Mississippi.Results from the case study indicate the costs of rerouting and congestion delays in the regional highway system and the rent costs of right-of-way in the regional railroad system are major factors of the indirect costs in the consumer surplus. Transportation system disruption due to a disaster results in “ripple effects ” throughout the entire transportation system of a metropolitan region. Many researchers have focused on the economic costs of transportation system disruptions in transportation-related industries, specifically within commerce and logistics, in the assessment of the regional economic costs. However, the foundation of an assessment of the regional economic costs of a disaster needs to include the evaluation of consumer surplus in addition to the direct cost for reconstruction of the regional transportation system. The objective of this study is to propose a method to estimate the regional consumer surplus based on indirect economic costs of a disaster on intermodal transportation systems in the context of diverting vehicles and trains.The computational methods used to assess the regional indirect economic costs sustained by the highway and railroad system can utilized clear available state departments of transpor tation (DOTs) and metropolitan planning organizations (MPOs) traffic models allowing prioritization of regional recovery plans after a disaster and strengthening of infrastructure before a disaster. Homeric Katrina is one of the most devastating hurricanes in the history of the United States. significance of Hurricane Katrina, a case study presented to evaluate consumer surplus in the Gulf Coast Region of Mississippi. Results from the case study indicate the costs of rerouting and congestion delays in the regional highway system and the rent costs of right-of-way in the regional railroad system are major factors of the indirect costs in the consumer surplus.