Office of Operations
21st Century Operations Using 21st Century Technologies

7.3 Evacuation Routing

Evacuations involve the movement of evacuees in their automobiles, and increasing the capacity of roadways to move the volume of evacuees is beneficial.

One current tool for this is lane-based routing. According to the Pergamon-Transportation Research Part A 37 (2003) 579–604 article “A Network Flow Model for Lane-Based Evacuation Routing,” lane-based routing “increases intersection approach capacities in directions favorable for evacuating a defined area. Lane-based routing can also be used to reduce [or eliminate] intersection crossing and merging conflicts.”

In addition, lane-based routing increases the throughput of the roadway during a time of need, much like the use of contra-flow lanes.

According to the article: “The 2000 Cerro Grande Fire evacuation in Los Alamos provided a valuable example of lane-based routing (LAC, 2001). Evacuees north of the main transportation artery in Los Alamos, Diamond Boulevard, were instructed to enter the westbound right lane of this Boulevard and remain in that lane. Evacuees originating south of Diamond Boulevard were instructed to enter the westbound left lane and remain in that lane. For this reason, vehicles north of Diamond did not merge with vehicles from the south. Furthermore, major intersections were placed in a state of uninterrupted flow. This allowed emergency managers to evacuate more than 11,000 residents in a few hours with only one major exit, a feat that would have taken many more hours under normal traffic control.”

February 7, 2006
Publication #FHWA–HOP-08-015