Editing Dual-mode bus (section)

{{Short description|Bus that can operate from two fuel sources}}
{{About|buses that can operate from two independent fuel sources|other hybrid technologies|Hybrid electric bus|and|Fuel cell bus|vehicles for two infrastructure types|Dual-mode vehicle}}
[[Image:MBTA Silver Line bus 1132.jpg|thumb|Boston [[Neoplan USA|Neoplan]] DMA-460LF dual-mode trolleybus, operating in diesel mode (with its [[trolley pole]]s lowered)]]
A '''dual-mode bus''' is a [[bus]] that can run independently on power from two different sources, typically electricity from [[overhead lines]] like a [[trolleybus]] or from [[Electric battery|batteries]] like a [[hybrid bus]], alternated with conventional [[fossil fuel]] (generally [[diesel fuel]]). In contrast to other hybrid buses, dual-mode buses can run forever exclusively on their electric power source (wires). Several of the examples listed below involve the use of dual-mode buses to travel through a tunnel on electric overhead power.

Many modern trolleybuses are equipped with auxiliary propulsion systems, either using a small [[diesel engine]] or battery power, allowing movement away from the overhead wires, called "off-wire" movement, but such vehicles are generally not considered to be dual-mode buses if their off-wire capability is very limited.  Examples include the fleet of about 300 trolleybuses in [[San Francisco]]<ref>{{Cite web |title=About Trolley Buses |url=http://www.sfmta.com/cms/mfleet/trolley.htm |archive-url=https://web.archive.org/web/20111218092119/http://www.sfmta.com/cms/mfleet/trolley.htm |archive-date=2011-12-18 |access-date=2009-12-15 |website=[[San Francisco Municipal Transportation Agency|San Francisco MTA]]}}</ref> and the trolleybuses used on a 2005-opened system in [[Rome]], Italy,<ref name="juts2009roma">Webb, Mary (ed.) (2009). ''Jane's Urban Transport Systems 2009-2010'', p. 195. Coulsdon (UK): [[Jane's Information Group]]. {{ISBN|978-0-7106-2903-6}}.</ref> which are capable of running on battery power only for short distances or short periods of time before needing recharging. The Rome vehicles are powered from overhead trolley wires over most of the 11.5-km route and only use battery power on the 500-metre section closest to the city centre.<ref name="juts2009roma"/> Dual mode trolleybuses in a number of Chinese cities can operate significant distances (8 to 10&nbsp;km) off-wire on battery power.<ref name=":0">{{Cite web |last=Luan |first=Xiaona 栾晓娜 |date=2014-06-26 |script-title=zh:上海无轨电车"复兴":全换成新型辫子车 车辆增加两倍 |url=http://sh.eastday.com/m/20140626/u1a8178158.html |archive-url=https://web.archive.org/web/20171011233240/http://sh.eastday.com/m/20140626/u1a8178158.html |archive-date=2017-10-11 |access-date=2017-10-11 |language=zh |script-website=zh:东方网}}</ref>