Risk evaluation in a transportation system

Methods for planning a transportation system in an urban area when exogenous events occur and/or in emergency conditions have received little attention from transportation system researchers, research institutions and journals. Models and algorithms specified and calibrated in ordinary conditions cannot be directly applied in emergency conditions. In this paper the risk problem in a transportation system is formalized and a methodology for evaluation is defined; a model for the evacuation simulation and design is proposed, and a test on a real system is reported. The risk problem is discussed to define measures for exposure reduction (evacuation) in a transportation system when an exogenous event occurs.