EFFICIENCY IN THE USE OF TRACTIVE ENERGY IN URBAN PUBLIC TRANSPORT

After defining the position of OECD nations on energy self-sufficiency, the author discusses the electric-energy and diesel-oil cycles in conjunction with comparative energy consumption of the various Italian public transit services. Both specific tractive energy consumption (in operations) and energy consumed in construction of transit systems are examined. It is concluded that energy efficiency between modes is not substantially changed by taking into account construction energy. Tractive consumption is then compared with average commercial speed, producing an overall tractive energy efficiency. This overall figure for both buses and streetcars is practically the same, while that for rapid transit systems is about twice as good. Despite this, the bus and tramway represent greater operating simplicity and can give coverage to light-traffic areas. While buses have greater flexibility with the same efficiency and commercial speed as tramways, the latter does have greater capacity. It is concluded that all three modes do complement each other in overall transit planning.