A new simulation model of fuel consumption and pollutant emissions in urban traffic

The atmospheric pollution is one of the most important impacts of vehicular tratlc; air pollution levels and the over-saturated traffic conditions constitute severe problems in many cities. A large number of models, with different characteristics, has been proposed in order to simulate tratlic flow and related pollutant emissions. In this paper, a fuel consumption and pollutant emission model is presente~ which has three interesting features. It is based on average tratlic speed, and so it can be coupled with macro traf6c simulators its range of validity (1 30 km/h) is well suited for urban congested traflic; it reproduces consumption and emissions in presenee of accelerations, decelerations, stop and go phenomena, typical of urban traftic. The model has been developed in three steps. Many experimental journeys have been effected by a test car in a large city (Naples); space and speed have been measured by every interval of 0.5 second. Fuel consumption and pollutant emissions have been computed second by second for each journey, using an instantaneous emission model, MODEM; afterwards, total fuel consumption and pollutant emissions in each journey have been computed. Statistical relationships between consumptionlemissions rates (g/km) and averagespeed (km/h), observedin the test runs, havebeen derivedby the least squares method.