Towards a Metropolitan Fundamental Diagram using Travel Survey Data

Abstract

Using travel diary data from 2000-2001 and 2010-12 this research examines fundamental traffic relationships at the metropolitan level. The results of this paper can help to explain the causes of some traffic phenomena. First, trip numbers on the network in the Minneapolis - St. Paul, Minnesota (Twin Cities) region show a bimodal diurnal pattern, with more trips in the afternoon. This relationship holds for full-time work and for non-work trips, but not part-time work trips. Second, network average speed by time of day can be explained by trip length and cumulative number of vehicles on the road. A clockwise hysteresis loop is found in the Metropolitan Fundamental Diagram in the morning period and a reverse process happens in the afternoon.