Editing Trolleybus (section)

==Transition to low-floor designs==
A significant change to trolleybus designs starting in the early 1990s was the introduction of [[low-floor]] models, which began only a few years after the first such models were introduced for [[motorbus]]es. These have gradually replaced [[high-floor]] designs, and by 2012, every existing trolleybus system in Western Europe had purchased low-floor trolleybuses, with the [[Trolleybuses in La Spezia|La Spezia (Italy) system]] being the last one to do so,<ref name="tm305-p119">''Trolleybus Magazine'' No. 305 (September–October 2012), p. 119.</ref> and several systems in other parts of the world have purchased low-floor vehicles.

In the United States, some transit agencies had already begun to accommodate persons in [[wheelchair]]s by purchasing buses with [[wheelchair lift]]s, and early examples of fleets of lift-equipped trolleybuses included 109 [[AM General]] trolleybuses built for the [[Trolleybuses in Seattle|Seattle trolleybus system]] in 1979 and the retrofitting of lifts in 1983 to 64 [[New Flyer|Flyer]] E800s in the [[Trolleybuses in Dayton|Dayton system]]'s fleet.<ref name="dearmond-tm141">DeArmond, R. C. (May–June 1985). "The Trolleybus System of Dayton, part 2". ''Trolleybus Magazine'' No. 141, pp. 49–64.</ref>{{rp|61}} The [[Americans with Disabilities Act of 1990]] required that all new transit vehicles placed into service after 1&nbsp;July 1993 be accessible to such passengers.<ref name="getting on board">"Getting on board" (July–August 1993). ''Trolleybus Magazine'' No. 190, pp. 86–87. National Trolleybus Association (UK).</ref>
[[File:NAW 705.jpg|thumb|One of the NAW/Hess [[Articulated bus|articulated]] trolleybuses delivered to Geneva in 1992, which were among the first production-series low-floor trolleybuses]]

Trolleybuses in other countries also began to introduce better access for the disabled in the 1990s, when the first two low-floor trolleybus models were introduced in Europe, both built in 1991, a "Swisstrolley" demonstrator built by Switzerland's [[Nutzfahrzeuggesellschaft Arbon & Wetzikon|NAW]]/[[Carrosserie Hess|Hess]] and an N6020 demonstrator built by [[Neoplan]].<ref name="tm179-p100">''Trolleybus Magazine'' No. 179 (September–October 1991), pp. 100–101.</ref><ref name=N6020>"The Neoplan N6020 Low-Floor Trolleybus". ''Trolleybus Magazine'' No. 183 (May–June 1992), p. 68.</ref> The first production-series low-floor trolleybuses were built in 1992: 13 by NAW for the [[Trolleybuses in Geneva|Geneva system]] and 10 [[Gräf & Stift]] for the {{Interlanguage link|Trolleybuses in Innsbruck|de|3=Oberleitungsbus Innsbruck|lt=Innsbruck system}}. By 1995, such vehicles were also being made by several other European manufacturers, including [[Škoda Works|Skoda]], [[Società Italiana Ernesto Breda|Breda]], [[Ikarus (Hungarian company)|Ikarus]], and [[Van Hool]].<ref name="braddock1995">Braddock, Andrew (March–April 1995). "Low-floor Trolleybuses – Making Access Easier". ''Trolleybus Magazine'' No. 200, pp. 30–37.</ref> The first [[Solaris Bus & Coach|Solaris]] "Trollino" made its debut in early 2001.<ref name="turzanksi2012">Turzanski, Bohdan (March–April 2012). "Trollino 500, Part 1". ''Trolleybus Magazine'' No. 302, pp. 28–35.</ref>{{rp|30}} In the former Soviet Union countries, Belarus' [[Belkommunmash]] built its first low-floor trolleybus (model AKSM-333) in 1999,<ref name="tm226-p89">''Trolleybus Magazine'' No. 226 (July–August 1999), p. 89.</ref> and other manufacturers in the former Soviet countries joined the trend in the early 2000s.

However, because the lifespan of a trolleybus is typically longer than that of a motorbus, the budget allocation and purchase typically factored in the longevity; the introduction of low-floor vehicles applied pressures on operators to retire high-floor trolleybuses that were only a few years old and replace them with low-floor trolleybuses.<ref name="tm222-p122">"Low-floor or Long Life?" (November–December 1998). ''Trolleybus Magazine'' No. 222, p. 122. National Trolleybus Association (UK).</ref> Responses varied, with some systems keeping their high-floor fleets, and others retiring them early but, in many instances, selling them second-hand for continued use in countries where there was a demand for low-cost second-hand trolleybuses, in particular in Romania and Bulgaria. The [[Trolleybuses in Lausanne|Lausanne system]] dealt with this dilemma in the 1990s by purchasing new low-floor passenger [[trailer (vehicle)|trailers]] to be towed by its high-floor trolleybuses,<ref name="tm222-p122"/> a choice later also made by [[Trolleybuses in Lucerne|Lucerne]].

[[File:Vancouver trolley bus - New Flyer E60LFR.jpg|thumb|The [[Trolleybuses in Vancouver|Vancouver trolleybus system]] completed the transition to an exclusively low-floor fleet in 2009.]]
Outside Europe, 14 vehicles built by, and for, the [[Trolleybuses in Shanghai|Shanghai trolleybus system]] in mid-1999 were the first reported low-floor trolleybuses in Southeast Asia.<ref name="tm230-p39">''Trolleybus Magazine'' No. 230 (March–April 2000), p. 39.</ref> [[Trolleybuses in Wellington|Wellington, New Zealand]], took delivery of its first low-floor trolleybus in March 2003,<ref name="tm249-p39">''Trolleybus Magazine'' No. 249 (May–June 2003), p. 39.</ref> and by the end of 2009 had renewed its entire fleet with such vehicles.<ref name="bramley-tm306">Bramley, Rod (November–December 2012). "New Zealand: A 'Roller Coaster' Ride, Part 4". ''Trolleybus Magazine'' No. 306, pp. 126–134.</ref> Unlike Europe, where low floor means "100%" low floor from front to back, most "low floor" buses on other continents are actually only low-entry or part-low floor.

In the Americas, the first low-floor trolleybus was a [[Busscar]] vehicle supplied to the [[Trolleybuses in São Paulo|São Paulo EMTU system]] in 2001.<ref name="box-tm292">Box, Roland (July–August 2010). "More about the 2000s". ''Trolleybus Magazine'' No. 292, pp. 78–82. National Trolleybus Association (UK). {{ISSN|0266-7452}}.</ref> In North America, wheelchair lifts were again chosen<ref name="tm222-p122"/> for disabled access in new trolleybuses delivered to [[Trolleybuses in San Francisco|San Francisco]] in 1992–94, to [[Trolleybuses in Dayton|Dayton]] in 1996–1999, and to Seattle in 2001–2002, but the first low-floor trolleybus was built in 2003, with the first of 28 Neoplan vehicles for the [[Trolleybuses in Greater Boston|Boston system]].<ref name="box-tm292"/> Subsequently, the [[Trolleybuses in Vancouver|Vancouver system]] and the [[Trolleybuses in Philadelphia|Philadelphia system]] have converted entirely to low-floor vehicles, and in 2013 the Seattle and Dayton systems both placed orders for their first low-floor trolleybuses. Outside São Paulo, almost all trolleybuses currently in service in Latin America are high-floor models built before 2000. However, in 2013, the first domestically manufactured low-floor trolleybuses were introduced in both Argentina and Mexico.<ref name="tm311"/>{{rp|134}}

With regard to non-passenger aspects of vehicle design, the transition from high-floor to low-floor has meant that some equipment previously placed under the floor has been moved to the roof.<ref name="getting on board"/> Some transit operators have needed to modify their maintenance facilities to accommodate this change, a one-time expense.