Selecting routes to minimize urban travel time

Urban regions contain a hierarchy of roadways, ranging from a dense network of low speed local roadways to sparser networks of higher speed roadways. Because minimizing travel time is usually more important than minimizing travel distance, vehicles may detour from the route of shortest distance to gain access to higher speed roadways. This paper uses continuous space models to analyze several urban travel decisions in which a driver must select between the shortest route on relatively low speed roadways and a longer route which includes travel on higher speed roadways. Results are presented graphically for deciding when to detour to faster roadways. Parallel and intersecting high speed roadways and limited access highways are considered.