Estimating Vehicle Fuel Consumption in Urban Areas.

The work described here was undertaken within the context of a research project whose main aim is the modelling of area-wide effects of traffic management measures through traffic flow simulation and assignment techniques. Given that fuel conservation is an objective of national importance, it was thought that a tool which is to be used in the evaluation of traffic management schemes should include fuel consumption as one of the performance measures.

Relationships between fuel consumption under urban driving conditions and the inverse of average travel speed have been inferred from experimental tests. These results, as well as those obtained from computer simulation of traffic flow and vehicle performance, are discussed and a relationship which gives urban fuel consumption as a function of journey distance, total delayed time and the number of stops is put forward for the 'average urban passenger car' in the U.K. Possible refinements to this formulation are discussed.

The role that traffic management measures can play in energy conservation is placed in perspective by looking briefly at the national and urban fuel consumption patterns. A review of reported potential fuel savings from traffic management measures is also undertaken. The fuel consumption consequences of changing the common cycle time for a co-ordinated system of signalised intersections are shown using data from Liverpool City Centre and the SATURN traffic simulation/assignment model.