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Relationship between heavy vehicle speed limit and fleet fuel consumption on minor roads

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Wilson, G 
Morrison, G 
Midgley, W 


jats:p This paper investigates the traffic-related effects of a proposal to increase the speed limit from 40 mile/h to 50 mile/h, for heavy goods vehicles greater than 7.5 tonnes, on single carriageway roads. A ‘microscopic’ single carriageway traffic simulation is developed by combining the ‘enhanced intelligent driver model’ with a single carriageway gap-acceptance passing model. Fuel consumption estimates are made using engine characteristic maps and a ‘fuel optimal’ gear selection scheme, where vehicle trajectories from the traffic simulations are taken as input drive-cycles. Traffic congestion and fleet fuel consumption are specifically addressed, though implications regarding passing behaviour and traffic safety are also noted. Results indicate that the proposed 50 mile/h heavy goods vehicles speed limit would reduce traffic congestion by over 37% and increase fleet fuel consumption by approximately 0.5 L/100 km. </jats:p>



Exhaust emissions, power consumption, transport engineering, safety, automobile

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Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

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SAGE Publications
Engineering and Physical Sciences Research Council (EP/K00915X/1)
The authors would like to thank Justin Bishop and Niall Martin of Cambridge University Engineering Department for providing valuable data. The authors would also like to thank Rachael Dillon of Freight Transport Association for suggesting the project. This work was supported in part by the Centre for Sustainable Road Freight (SRF) and the Engineering and Physical Sciences Research Council (EPSRC) through Grant Ref EP/K00915X/1. At the time of writing, the members of the SRF were: Coca-Cola Enterprises, Denby Transport, DHL, Freight Transport Association, Haldex Brake Products, Goodyear Tires, John Lewis/Waitrose, Laing O’Rourke, Optrak, SDC Trailers, Tesco, Volvo Trucks, Warburtons, Wincanton.