Transportation network would be degraded under incident circumstance. If the change of demand side of the transportation system was not considered, the consequence of the incident would be overestimated. The demand vulnerability was proposed to evaluate the network’s ability to resist incidents by considering both the supply and the demand side of the system. A combined travel demand model and an accessibility measure based on the random utility theory were applied as the basis of the demand vulnerability index. A trial network presented the calculation of the index and its application for comparison of management schemes. The demand vulnerability analysis could be helpful for the planners and managers to take measures to enhance the network’s ability against incidents.