Emergency vehicles require good access to residences after a large scale disaster. In the Great Hanshin-Awaji Earthquake of January 17, 1995, in the Kobe area of Japan, the access of emergency vehicles to the sites where they were needed was severely hindered by the traffic chaos in the aftermath of the earthquake, obstructing lifesaving activities. The urgent need for improving the reliability of road networks, and especially the reliability of emergency pathways, was thus confirmed.