5.3 Long distance buses
Long distance buses are similar to standard city buses in technical specifications, but, due to a more comfortable interior, slightly heavier. A net weight of 18 t will be used for exemplification.
Fuel consumption will be less on highways and rural main roads than in an urban use pattern. An analysis of extensive tests ([LASTAUTO OMNIBUS]) as well as calculations of the average fuel consumption in Germany resulted in a value of 30 l of diesel fuel consumed per 100 km ([TREMOD 2001]) which is used for exemplification. A similar value of 29 l is also stated by [GREENFLEET 2002].
5.3.1 Specific energy savings
Long distance buses are mainly used for interurban travel in a more steady flow of traf- fic. Weight induced energy savings are therefore lower than for city buses. Estimates from [MAN 2002] state fuel savings of 0,04 l for a 100 kg weight reduction. This value amounts 20 % of the fuel savings stated for the standard city bus. Therefore also rela- tive energy savings in the range of 2.4 % are lower than assumed for the city bus.
Specific fuel savings [l/(100 km*100 kg)]
Relative energy savings [%]
Tab. 8: Specific and relative fuel savings of long distance buses
5.3.2 Life-time performance and energy savings
Long distance buses are generally only used for a few years by major bus operators. Afterwards, due to customer demands in respect to comfort, many buses are sold to smaller operators or exported. Manufacturers assume that these buses have an annual performance of about 100’000 to 120’000 km and are sold after 3 to 6 years ([MAN 2002]). These figures are also confirmed by Internet trade markets (e. g. http://www.yakoub.de/index.html; http://cat.workingwheels.com; http://www.used- buses.net) which sell many buses of this age and with the same performance. Some vehicles are sold with a performance of up to 1.2 Mio. km. Estimates of the Association of German Transport Operators (“Verband Deutscher Verkehrsunternehmen” [VDV 2002]) state life-time performances of 0.8 to 1.1 Mio. km in Germany. The “Motorcoach Census 2000” of the American Bus Association ([ABA 2000]) states that the average bus travelled about 81’000 km in 1999. The range of annual performance, however, is between less than 16’000 km and over 160’000 km. The average value is in line with the values stated by the Association of German Transport Operators ([VDV 2002]).