A trolleybus is an electric bus that draws power from dual overhead wires using spring-loaded trolley poles. Two wires, and two trolley poles, are required to complete the electrical circuit. This differs from a tram or streetcar, which normally uses the track as the return path, needing only one wire and one pole. They are also distinct from other kinds of electric buses, which usually rely on batteries. Power is most commonly supplied as 600-volt direct current, but there are exceptions.
The Boston-area trolleybus system formed part of the public transportation network serving Greater Boston in the U.S. state of Massachusetts. It opened on April 11, 1936, with a large network operating for the next quarter-century. Measured by fleet size, the Boston-area system was the second-largest trolleybus system in the United States at its peak, with only the Chicago system having more trolleybuses than Boston's 463. After 1963, the only remaining portion was a four-route cluster operating from the Harvard bus tunnel at Harvard station, running through Cambridge, Belmont, and Watertown. The Massachusetts Bay Transportation Authority took over the routes in 1964.
An electric bus is a bus that is propelled using electric motors as opposed to an internal combustion engine. Electric buses can store the needed electricity on board, or be fed continuously from an external source. The majority of buses storing electricity are battery electric buses, where the electric motor obtains energy from an onboard battery pack, although examples of other storage modes do exist, such as the gyrobus which uses flywheel energy storage. When electricity is not stored on board, it is supplied by contact with outside power sources. For example, overhead wires as in the trolleybus, or with a ground-level power supply, or through inductive charging.
Gillig is an American designer and manufacturer of buses. The company headquarters, along with its manufacturing operations, is located in Livermore, California. By volume, Gillig is the second-largest transit bus manufacturer in North America. As of 2013, Gillig had an approximate 31 percent market share of the combined United States and Canadian heavy-duty transit bus manufacturing industry, based on the number of equivalent unit deliveries.
Guided Light Transit was the name of guided bus technology and associated infrastructure designed and manufactured by Bombardier Transportation. It was installed in two French cities: Nancy and Caen. The Caen system was closed in 2017 and replaced by conventional trams, while the Nancy system was closed in March 2023 and is to be replaced by trolleybuses.
Shanghai has around 2000 formal bus lines, served by more than 10 bus companies. In the past, Bashi, Dazhong, Guanzhong and Qiangsheng were the four largest; around 2009 they merged to become Bashi Group Companies, including Bashi No.1-6 Bus Passenger Service Companies, Bashi Tram, Bashi Xinxin and Chongming Company, Baoshan Company and Jinshan Company. Each Suburban district also renewed with one company serving each district. Around 2015, Bashi No.1 Passenger Service and Bashi Tram merged to be Bashi No.1 Company, Bashi No.2 Passenger Service became Bashi No.2 Company, Bashi No.3, No.4 Passenger Service merged to be Bashi No.3 Company, Bashi No.6 Passenger Service became Bashi No.4 Company, and Bashi No.5 Passenger Service and Baoshan Company became Bashi No.5 Company.
A trolleytruck is a trolleybus-like vehicle used for carrying cargo instead of passengers. A trolleytruck is usually a type of electric truck powered by two overhead wires, from which it draws electricity using two trolley poles. Two current collectors are required in order to supply and return current, because the return current cannot pass to the ground since trolleytrucks use tires that are insulators. Lower powered trucks, such as might be seen on the streets of a city, tend to use trolley poles for current collection. Higher powered trucks, such as those used for large construction or mining projects, may exceed the power capacity of trolley poles and have to use pantographs instead. Trolleytrucks have been used in various places around the world and are still in use in cities in Russia and Ukraine, as well as at mines in North America and Africa. Because they draw power from the mains, trolleytrucks can use renewable energy sources – modern trolleytrucks systems are under test in Sweden and Germany along highways using diesel–electric hybrids to reduce emissions.
A battery electric bus is an electric bus that is driven by an electric motor and obtains energy from on-board batteries. Many trolleybuses use batteries as an auxiliary or emergency power source.
Trolleybuses in Wellington were part of the Wellington public transport system from 1924 until 1932 and again from 1949 until 2017. It was the last trolleybus system operating commercially in Oceania and the last major system operating in a country where driving is on the left side of the road.
With five different modes of transport, the San Francisco Municipal Railway runs one of the most diverse fleets of vehicles in the United States. Roughly 550 diesel-electric hybrid buses, 300 electric trolleybuses, 250 modern light rail vehicles, 50 historic streetcars and 40 cable cars see active duty.
The Gillig Low Floor is a transit bus manufactured by Gillig since 1997. The second low-floor bus design introduced in the United States, the Low Floor originally served as a second product range for the company alongside the Gillig Phantom. As transit bus operators shifted toward low-floor designs, the Low Floor has replaced the Phantom entirely, becoming the sole vehicle platform offered by the company since 2008.
The Rome trolleybus system forms part of the public transport network of the city and comune of Rome, Italy. In operation since 2005, the current system comprises three routes.
The Vancouver trolley bus system forms part of the TransLink public transport network serving Metro Vancouver in the Canadian province of British Columbia. Opened in 1948, the system was originally owned and operated by the British Columbia Electric Railway. By 1954, Vancouver had the largest trolley bus fleet in Canada, with 327 units, and the fleet grew to an all-time peak of 352 in early 1957. There were 19 routes by 1955 and a peak of 20 by the second quarter of 1957. The last route to open in the 1950s was the only express trolley bus service that ever existed in Canada. Several, mostly short, extensions to the system were constructed in the 1980s and later.
The Seattle trolleybus system forms part of the public transportation network in the city of Seattle, Washington, operated by King County Metro. Originally opened on April 28, 1940, the network consists of 15 routes, with 174 trolleybuses operating on 68 miles (109 km) of two-way parallel overhead lines. As of the second quarter of 2023, the system carries riders on an average of 41,000 trips per weekday, comprising about 18 percent of King County Metro's total daily ridership. At present in Seattle, a very common alternative term for trolleybus is trolley.
The Dayton trolleybus system forms part of the public transportation network serving Dayton, in the state of Ohio, United States. Opened on April 23, 1933, it presently comprises five lines, and is operated by the Greater Dayton Regional Transit Authority, with a fleet of 45 trolleybuses. In 2022, the system had a ridership of 1,813,600, or about 6,300 per weekday as of the second quarter of 2023.
The Philadelphia trolleybus system forms part of the public transportation network serving Philadelphia, in the state of Pennsylvania, United States. It opened on October 14, 1923, and is now the second-longest-lived trolleybus system in the world. One of only four such systems currently operating in the U.S., it presently comprises three lines and is operated by the Southeastern Pennsylvania Transportation Authority (SEPTA), with a fleet of 38 trolleybuses, or trackless trolleys as SEPTA calls them. The three surviving routes serve North and Northeast Philadelphia and connect with SEPTA's Market–Frankford rapid transit line.
The Shanghai trolleybus system is a system of trolleybuses forming part of the public transport network in the city of Shanghai, China. Of more than 300 trolleybus systems in operation worldwide, the Shanghai system is the oldest. The system turned 100 years old in November 2014 and was the first trolleybus system anywhere in the world to reach that milestone.
As of 2012 there were around 300 cities or metropolitan areas where trolleybuses were operated, and more than 500 additional trolleybus systems have existed in the past. For complete lists of trolleybus systems by location, with dates of opening and closure, see List of trolleybus systems and the related lists indexed there.
As of 2017, King County Metro operates the 10th largest fleet of buses in the United States, with a total of 1,540 buses.
