Bi-articulated bus
A bi-articulated bus or double-articulated bus is a type of high-capacity articulated bus with an extra axle and a second articulation joint, as well as extended length, bi-articulated buses tend to be employed in high-frequency core routes or bus rapid transit schemes rather than in conventional bus routes.
Design considerations
Common bi-articulated buses resemble rail vehicles in design. They often have elevated train-type doors instead of traditional bus doors to use dedicated stations. Payment is typically made at a bus station using a fare gate rather than on the bus.Compared to using multiple smaller buses on a route, challenges using a bi-articulated bus include:
- difficulties maneuvering in traffic
- an increased turning radius
- the need to have extended length station platforms
- reduced frequency of service
- less flexibility for scheduling, routing, and maintenance.
Early versions
In the late 1980s, the French manufacturers Renault and Heuliez Bus developed the "Mégabus", a bi-articulated high-floor bus. The demonstrator Mégabus visited transit agencies throughout France, but the only city to order them was Bordeaux. These buses, now retired, were used on Bordeaux's bus route 7 until the city's tram system opened in 2004.Hungarian bus manufacturer Ikarus also developed a bi-articulated bus prototype, the Ikarus 293, in the early 1990s.
In Bucharest, the ITB operated a double articulated trolleybus, made by adding a modified section between the first and the last sections of a DAC 117E articulated trolleybus, one of the sections coming from a damaged DAC 117E. This vehicle was built to fulfill the need of high capacity person transportation, which was proving difficult for the ITB in 1988, when the prototype was made. However, the DAC 117E's 125 kW traction motor proved insufficient for such a heavy vehicle, let alone the weight of passengers when it operated at full capacity. As a result, the vehicle was very slow and had trouble operating on grades, especially the incline between Cișmigiu Park and University Square. It also had trouble making sharp turns and was difficult to control, especially on snow or ice. This trolleybus was operated on long lines with wide roads and no major turns except the end of the lines like 69 and 90, but occasionally entered on lines 85, 66, 79 and 86. Bucharest traffic became increasingly intense in the very late 1990s, and RATB sought shorter trolleybuses. The DAC 122E was withdrawn from regular service, being occasionally used on lines 69 and 90 until 2000 when it was fully removed from service, displaced by the then-new Ikarus 415Ts and scrapped. Bucharest no longer operates bi-articulated vehicles due to high traffic levels, which is also the reason why between 2007 and 2018, the RATB refused to operate normal articulated buses.
Use
A bi-articulated bus is a long vehicle and usually requires a specially trained driver, as maneuvering can be difficult. Articulated electric trolleybuses can be difficult to control, with their motors producing momentary peak power in excess of 600 kilowatts. The trailer section of a "puller" bus can be subject to unusual centripetal forces, which many people can find uncomfortable, although this is not an issue with "pushers". Bi-articulated buses are difficult to reverse park as joints force the bus into a zig-zag shape.The transit system that has used bi-articulated buses the longest is the Rede Integrada de Transporte, in Curitiba, Brazil, which provides a type of service that has come to be known – particularly in American English – as bus rapid transit, where buses run in dedicated lanes and stop only at enclosed stations. Use of bi-articulated buses began in 1992, with vehicles manufactured by Volvo and Marcopolo/Ciferal, able to carry up to 270 passengers. Each bi-articulated bus is equipped with five doors where passengers can quickly load and unload. Buses stop only at enclosed, tube-shaped stations, where passengers pre-pay the fare and then board at the same level as the vehicle floor. Curitiba has over 170 bi-articulated buses in operation on routes serving five main corridors of dedicated bus lanes. These buses run on an average period of 50 seconds during peak hours.
Colombia
in Bogotá has operated bi-articulated buses since 2009, having purchased 120 by 2013. In 2020 it will receive a further 58.Brazil
The Brazilian bus body manufacturers Marcopolo, CAIO, Busscar and most lately Neobus have made many bi-articulated buses on top of Volvo chassis. They are currently used in Rio de Janeiro, São Paulo, Campinas, Goiânia, Curitiba and, outside of Brazil, in Bogotá, Colombia.In November 2016, Volvo launched the Volvo Gran Artic 300 bi-bus chassis, specifically developed in Brazil for BRT systems. At long, this chassis is capable of carrying 300 passengers.
Canada
In November 2019, Quebec City's Réseau de transport de la Capitale announced that it is planning to open the city's first BRT line along Boulevard Charest by 2026, utilizing a fleet of bi-articulated electric buses. Quebec City is the first and only in North American city to make such an announcement.China
The Chinese manufacturer Youngman developed the JNP6250G bi-articulated bus for 300 passengers with assistance from Neoplan. In 2007, these buses appeared on trial service in Beijing and were thought to be the world's longest, at long.Czechia
The Belgian manufacturer Van Hool offers a bi-articulated bus with a capacity of about 180 passengers. This bus is used in Prague, with line 119 connecting the Václav Havel Airport Prague with the rest of the city.Germany
The Belgian manufacturer Van Hool offers a bi-articulated bus with a capacity of about 180 passengers. These buses are used in the German cities of Aachen and Hamburg, where single-articulated buses alone were not able to handle the huge number of passengers per day. In Hamburg they were retired in 2018 after 13 years of service as they started to require more and more maintenance due to their growing age and an unusual level of wear and tear, caused by the second articulation joint.In 2012, Fraunhofer IVI introduced the AutoTram Extra Grand in Dresden. With overall length of it is the longest bus in service with a passenger capacity of 256. Its unique 5-axle design is made possible using advanced computer controlled steering on the 3 trailing axles.
Luxembourg
The Swiss manufacturer Hess produces a bi-articulated, hybrid-engine bus based on the LighTram. This type is currently in use for the Luxembourgian bus operator Voyages Emile Weber.The Netherlands
The Belgian manufacturer Van Hool offers a bi-articulated bus with a capacity of about 180 passengers. In September 2002, fifteen were deployed on lines 11 and 12 in the Dutch city of Utrecht, connecting the downtown railway station to office, college and university buildings at the edge of the city. Twelve more have been added since.From August 2014 to 2016, Swiss manufacturer Hess's bi-articulated LighTram busses were in service in Groningen, Netherlands on the route from the main train station via the city center to the university north of the city. In 2016 these busses were moved to Utrecht because the few stops and higher speeds on this line made the hybrid engine perform poorly.