Title : Measuring the Effects of Traffic Congestion on Fuel

1 Nowadays, road transportation sector is responsible for a considerable amount of the total energy 2 consumption, also contributing to about 20-30% of the total man-made CO2 emissions 3 worldwide. 4 In metropolitan areas, the problem is compounded by the effect of traffic congestion. 5 Transport models, online route planners, and the latest versions of on-board navigators do take 6 into account traffic variability in their calculation of travel times. However, the effect of traffic 7 congestion on fuel consumption is hardly taken into consideration, thereby introducing a 8 considerable distortion in the result and consequently, the traveler decision process. 9 The aim of this paper is to investigate in detail, how traffic congestion affects fuel 10 consumption and to evaluate the importance of including traffic congestion in modeling and 11 driver information systems. This analysis is based on empirical data collected from some 12 itineraries of a metropolitan motorway and streets of the metropolitan area of Madrid, Spain. 13 Specifically, a total of 3,800 trips were recorded with three vehicles under different traffic 14 conditions and driving styles. The results show considerable increase in fuel consumption under 15 congested traffic conditions compared with free flow conditions, but also points to the 16 differences depending on the type of itinerary. 17 18