Bus rapid transit
Overview
 
Bus rapid transit is a term applied to a variety of public transportation systems using bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

es to provide faster, more efficient service than an ordinary bus line. Often this is achieved by making improvements to existing infrastructure, vehicles and scheduling. The goal of these systems is to approach the service quality of rail transit while still enjoying the cost savings and flexibility of bus transit.
Encyclopedia
Bus rapid transit is a term applied to a variety of public transportation systems using bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

es to provide faster, more efficient service than an ordinary bus line. Often this is achieved by making improvements to existing infrastructure, vehicles and scheduling. The goal of these systems is to approach the service quality of rail transit while still enjoying the cost savings and flexibility of bus transit. The expression BRT is mainly used in North America; in Europe and Australia, it is often called a busway, while elsewhere, it may be called a quality bus.

Etymology

Bus rapid transit takes part of its name from rail rapid transit
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...

, which describes a high-capacity urban public-transit system with its own right-of-way, multiple-car trains at short headway
Headway
Headway is a measurement of the distance/time between vehicles in a transit system. The precise definition varies depending on the application, but it is most commonly measured as the distance from the tip of one vehicle to the tip of the next one behind it, expressed as the time it will take for...

s, and longer stop spacing than traditional streetcars and buses. BRT, however, uses buses on a wide variety of rights-of-way, including mixed traffic, dedicated lanes on surface streets, and busways completely separated from traffic.

Typical transit speeds of BRT systems range from 17 to 30 mph (7.6 to 13.4 ), which can compare with surface running light rail
Light rail
Light rail or light rail transit is a form of urban rail public transportation that generally has a lower capacity and lower speed than heavy rail and metro systems, but higher capacity and higher speed than traditional street-running tram systems...

.

History

The first BRT system in the world was the Rede Integrada de Transporte
Rede Integrada de Transporte
Rede Integrada de Transporte is a bus rapid transit system in Curitiba, Brazil. The RIT was implemented in 1974 becoming the first BRT system in the world....

 (RIT, translated as "Integrated Transportation Network"), implemented in Curitiba
Curitiba
Curitiba is the capital of the Brazilian state of Paraná. It is the largest city with the biggest economy of both Paraná and southern Brazil. The population of Curitiba numbers approximately 1.75 million people and the latest GDP figures for the city surpass US$61 billion according to...

, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 in 1974.

Main features

BRT systems come in a variety of forms, such as dedicated busways with their own rights-of-way (such as Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...

's Transitway or Pittsburgh's Martin Luther King Jr. East Busway
Martin Luther King Jr. East Busway
The Martin Luther King Jr. East Busway is a two-lane dedicated bus-only highway serving the city of Pittsburgh and many of its eastern neighborhoods and suburbs. The original segment of the busway opened in February 1983, running between Downtown Pittsburgh and Edgewood, a length of 6.8 miles...

), bus services using HOV
High-occupancy vehicle lane
In transportation engineering and transportation planning, a high-occupancy vehicle lane is a lane reserved for vehicles with a driver and one or more passengers...

 lanes
, dedicated freeway lanes (such as Honolulu's CityExpress) and limited stop buses on pre-existing routes.

An ideal bus rapid transit service would be expected to include most of the following features:
  • Bus only, grade-separated (or at-grade exclusive) right-of-way: A dedicated bus lane
    Bus lane
    A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport that would be otherwise held up by traffic congestion...

     allows the bus to operate separately, without interference from other modes of traffic. Although buses have a long turning radius, dedicated busways can be engineered to tighter standards than an open roadway, reducing construction costs while still assuring safe operation.
    • A bus-only right-of-way may be elevated, depressed, or routed through a tunnel. An abandoned rail right-of-way is sometimes used.
    • A transit mall
      Transit mall
      A transit mall is a street, or set of streets, in a city or town along which automobile traffic is prohibited or greatly restricted and only public transit vehicles, bicycles and pedestrians are permitted....

       or bus street can be created in city centers by dedicating all lanes of a city street to the exclusive use of buses.
    • Low-cost infrastructure elements that can increase the speed and reliability of bus service include bus turnout
      Bus turnout
      A bus turnout, bus pullout, bus bay, bus lay-by , or off-line bus stop is a special zone on the side of the main roadway for primarily buses to stop for a designated bus stop in order to pick up and drop off passengers...

      s, boarding islands, and curb realignments.

  • Comprehensive coverage: BRT systems can either share existing roadways with other traffic, or use bus lane
    Bus lane
    A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport that would be otherwise held up by traffic congestion...

    s
    that restrict other traffic from a portion of the roadway. Service along public roadways can be improved by taking advantage of bus priority methods.

  • Serves a diverse market with high-frequency all day service: A BRT network with comprehensive coverage can serve a diverse market (all income ranges) by moving large numbers of people between locations quickly and reliably throughout the day, while maintaining a comfortable riding experience. These characteristics are essential to satisfying the demands of a diverse market or offering high-frequency service without heavy subsidy.


  • Bus priority
    Bus priority
    Bus priority or transit signal priority is a name for various techniques to speed up bus public transport services at intersections with traffic signals amongst other methods. Trams and light rail vehicles can also be given priority...

    : Preferential treatment of buses at intersections can involve the extension of green time or actuation of the green light at signalized intersections upon detection of an approaching bus. Intersection priority can be particularly helpful when implemented in conjunction with bus lanes or bus streets, because general-purpose traffic does not intervene between buses and traffic signals.

  • Vehicles with tram-like characteristics: Recent technological developments such as bi-articulated bus
    Bi-articulated bus
    A bi-articulated bus or double articulated bus is an extension of an articulated bus in that it has three passenger compartment sections instead of two. This also involves the addition of an extra axle...

    es and guided bus
    Guided bus
    Guided buses are buses steered for part or all of their route by external means, usually on a dedicated track. This track, which often parallels existing roads, excludes other traffic, permitting the maintenance of reliable schedules on heavily used corridors even during rush hours.Guidance systems...

    es have benefited the set-up of BRT systems. The main developments are:
    • Improved riding quality (Use of guided bus
      Guided bus
      Guided buses are buses steered for part or all of their route by external means, usually on a dedicated track. This track, which often parallels existing roads, excludes other traffic, permitting the maintenance of reliable schedules on heavily used corridors even during rush hours.Guidance systems...

       and powertrain control
      Powertrain Control Module
      A Powertrain Control Module, abbreviated PCM, is an automotive component, an electronic control unit , used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit and the transmission control unit. It commonly controls more than 5 factors in the car or...

       technologies for smoother operation),
    • Increased capacity (articulated
      Articulated bus
      An articulated bus is an articulated vehicle used in public transportation. It is usually a single-deck design, and comprises two rigid sections linked by a pivoting joint...

       and double-decker
      Double-decker bus
      A double-decker bus is a bus that has two storeys or 'decks'. Global usage of this type of bus is more common in outer touring than in its intra-urban transportion role. Double-decker buses are also commonly found in certain parts of Europe, Asia, and former British colonies and protectorates...

      ),
    • Reduced operating costs (hybrid electric powertrain).

  • A specific image with a brand name: (e.g. Viva, Max, TransMilenio, Metropolitano, Select) marking stops and stations as well as the buses. The system's brand identity contributes to its attractiveness as an alternative to driving cars.

  • Off-bus fare collection: Conventional on-board fare collection slows the boarding process, particularly when different fares are collected for different destinations and/or classes of passengers. Some BRT systems collect fares upon entering an enclosed bus station
    Bus station
    A bus station is a structure where city or intercity buses stop to pick up and drop off passengers. It is larger than a bus stop, which is usually simply a place on the roadside, where buses can stop...

     or shelter area prior to bus arrivals (similar to fare collection at a kiosk prior to entering a subway system). This allows passengers to board quickly through all doors of a stopped bus.

  • Level boarding: Many BRT systems also use low-floor bus
    Low-floor bus
    A low-floor bus is a bus that has no steps between one or more entrances and part or all of the passenger cabin. Being low floor improves the accessibility of the bus for the public, particularly the elderly or infirm, or those with push chairs, and increasingly, those in wheelchairs.In the modern...

    es (or high-level platforms with high-floor buses) to speed passenger boardings and enhance accessibility.

  • Stations: High-quality BRT systems feature significant investment in enclosed stations which may incorporate attractive sliding glass doors, staffed ticket booths, information booths, and other more standard features listed above. This style of station is seen throughout Colombia, in (Bogotá
    Bogotá
    Bogotá, Distrito Capital , from 1991 to 2000 called Santa Fé de Bogotá, is the capital, and largest city, of Colombia. It is also designated by the national constitution as the capital of the department of Cundinamarca, even though the city of Bogotá now comprises an independent Capital district...

    's TransMilenio
    TransMilenio
    TransMilenio is a bus rapid transit system that serves Bogotá, the capital of Colombia. The system opened to the public in December 2000, covering Av. Caracas and Calle 80...

    , Cali
    Calì
    Calì, also written in English as Cali, is an Italian surname, widespread mainly in the Ionian side of Sicily.For the surname Calì is assumed the origin of the Greek word kalos , or from its Sanskrit root kali, "time."The surname refers to:...

    's MIO
    Masivo Integrado de Occidente
    The Masivo Integrado de Occidente , also referred to as MIO, is a bus rapid transit system that serves Santiago de Cali, Colombia. The system is operated through articulated buses which move in dedicated lanes. Approximately the 97% of the spatial perimeter of the city will be involved by this...

    , Bucaramanga's Metrolinea
    Metrolinea
    Metrolínea is the Masive Transport System that operates in the city of Bucaramanga, in the department of Santander, Colombia.It Operates green buses and is managed by Tisa, an enterprise that is managed by Dr. Carlos Arenas, a Bucaramangaian engineer. Metroline counts with 50 buses, and goes thru...

    , Pereira's Megabús
    Megabús
    The Megabús is a bus rapid transit system that serves the cities of Pereira and Dosquebradas in Colombia. The Megabús covers the most parts of the cities using the Av. 30 de Agosto and the Av. del Ferrocarril in Pereira, and the Av. Simon Bolívar in Dosquebradas. There are also used the Carrera...

    ) and in most other Latin American BRT systems developed in the last decade. This design is also used in Johannesburg
    Johannesburg
    Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...

    's Rea Vaya. The term "station" is more flexibly applied in North America and ranges from enclosed waiting areas (Ottawa
    Ottawa
    Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...

     and Cleveland), to large open-sided shelters (Los Angeles
    Los Ángeles
    Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...

    ), to simple signposts.


All of the above characteristics were noted as features of Bogotá's TransMilenio
TransMilenio
TransMilenio is a bus rapid transit system that serves Bogotá, the capital of Colombia. The system opened to the public in December 2000, covering Av. Caracas and Calle 80...

, described as a "model BRT system" in the National Bus Rapid Transit Institute's May 2006 report. TransMilenio serves Bogotá with high-capacity articulated buses, which passengers can board through three doors. Bi-articulated bus
Bi-articulated bus
A bi-articulated bus or double articulated bus is an extension of an articulated bus in that it has three passenger compartment sections instead of two. This also involves the addition of an extra axle...

es are also now used on the busiest routes. A smart card
Smart card
A smart card, chip card, or integrated circuit card , is any pocket-sized card with embedded integrated circuits. A smart card or microprocessor cards contain volatile memory and microprocessor components. The card is made of plastic, generally polyvinyl chloride, but sometimes acrylonitrile...

 system is used for off-board fare collection. Nevertheless, despite moving 45,000 ppdph, Transmilenio faces huge problems (especially during peak hours), in terms of not being quite organized, nor having the necessary capacity for handling the high passenger volume, a situation not being limited to peak hours only, but at most times along the day.

In some cities and large towns, such as Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...

, Essen
Essen
- Origin of the name :In German-speaking countries, the name of the city Essen often causes confusion as to its origins, because it is commonly known as the German infinitive of the verb for the act of eating, and/or the German noun for food. Although scholars still dispute the interpretation of...

 (Germany), Pittsburgh, and Seattle, it is common for a right of way exclusive to public transport to be shared by both light rail and buses, and in some cases taxis.

Comparison with other forms of mass transit

BRT attempts to combine the advantages of a rail system (notably a partially or completely dedicated right-of-way, which greatly improves punctuality and reliability) with the advantages of a bus system (low construction and way maintenance costs, low vehicle costs, right-of-way not required for entire length, and the ability of feeder bus services to join a trunk busway). In Latin America and cities in Asia, the BRT service is usually compared to metro-quality rail, and normally results in consistently similar enclosed stations featuring smartcard turnstiles and level-platform boarding. In North America, the BRT is usually compared to LRT-quality rail, and typically results in open-air shelters with ticket-dispenser machines, or even just curbside signposts difficult to distinguish from other roadside visual clutter.

Comparison with conventional bus routes

When available, the dedicated right-of-way lanes of BRT systems allow them an increased average vehicle speed bypassing traffic congestion, to provide more passenger miles with the same number of vehicles and personnel than conventional bus services. A smoother ride can also be expected, because the BRT is not immersed in stop-and-go traffic. BRT services usually feature higher frequency service than conventional routes; Latin American systems rely heavily on short headways to achieve their ridership capacity.

But when compared to normal bus service in mixed traffic, addition of BRT dedicated lanes requires wider roads or reduction of mixed traffic lanes.

Comparison with light rail

Primary considerations in choosing between light rail and bus rapid transit systems are the differences in construction costs, operating costs, capacity, adaptability and image.

Proponents of light rail point out that the operating costs of BRT are not necessarily lower than light rail. The typically larger light rail vehicles enjoy reduced labor costs per passenger, and the unit capital cost per passenger can be lower than a BRT system.
In contrast to BRT, light rail and tram
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

 systems require the placement of rails for the entire line. The tram usually avoids the high additional costs for engineering structures, such as tunnels, that need to be built for metro rail systems. Properly maintained rail tends to provide a smoother ride, making it more attractive to riders than road-based systems. As of 2011, there is no widely-acknowledged research that has successfully and unequivocally proven that passengers prefer rail, once other factors such as frequency and reliability are allowed for.

With similar dwell times in stations, the capacity of rail systems would scale with the length of the train. For instance, a light rail system running on two-minute headways with 200-passenger cars operating as single units could carry 6,000 passengers per hour (pph). Theoretically, this same system should carry 12,000 pph with two-car trains, and 24,000 pph with four-car trains. In practice, real-world delays and headway disruptions cause a practical limitation of around 12,000 to 19,000 pph for light rail systems.

A survey by the UK Transport Research Laboratory reported the following peak passenger flows (passengers per hour) for BRT transitways. These were based on actual verifiable counts in real world conditions:
  • Designated Lane: Ankara
    Ankara
    Ankara is the capital of Turkey and the country's second largest city after Istanbul. The city has a mean elevation of , and as of 2010 the metropolitan area in the entire Ankara Province had a population of 4.4 million....

    , Istanbul
    Istanbul
    Istanbul , historically known as Byzantium and Constantinople , is the largest city of Turkey. Istanbul metropolitan province had 13.26 million people living in it as of December, 2010, which is 18% of Turkey's population and the 3rd largest metropolitan area in Europe after London and...

    , Abidjan
    Abidjan
    Abidjan is the economic and former official capital of Côte d'Ivoire, while the current capital is Yamoussoukro. it was the largest city in the nation and the third-largest French-speaking city in the world, after Paris, and Kinshasa but before Montreal...

     7,300 – 19,500
  • Designated Lanes with Feeders Curitiba
    Curitiba
    Curitiba is the capital of the Brazilian state of Paraná. It is the largest city with the biggest economy of both Paraná and southern Brazil. The population of Curitiba numbers approximately 1.75 million people and the latest GDP figures for the city surpass US$61 billion according to...

    , Brazil
    Brazil
    Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

     13,900 – 24,100
  • Designated Lanes with Bus Ordering (Travelling in Clusters) Porto Alegre
    Porto Alegre
    Porto Alegre is the tenth most populous municipality in Brazil, with 1,409,939 inhabitants, and the centre of Brazil's fourth largest metropolitan area . It is also the capital city of the southernmost Brazilian state of Rio Grande do Sul. The city is the southernmost capital city of a Brazilian...

     17,500 – 18,300
  • Designated Lanes with Overlapping Routes, Passing at Stations and Express Routes Belo Horizonte
    Belo Horizonte
    Belo Horizonte is the capital of and largest city in the state of Minas Gerais, located in the southeastern region of Brazil. It is the third largest metropolitan area in the country...

    , São Paulo
    São Paulo
    São Paulo is the largest city in Brazil, the largest city in the southern hemisphere and South America, and the world's seventh largest city by population. The metropolis is anchor to the São Paulo metropolitan area, ranked as the second-most populous metropolitan area in the Americas and among...

     15,800 - 20,300
  • TransMilenio
    TransMilenio
    TransMilenio is a bus rapid transit system that serves Bogotá, the capital of Colombia. The system opened to the public in December 2000, covering Av. Caracas and Calle 80...

    , Bogotá
    Bogotá
    Bogotá, Distrito Capital , from 1991 to 2000 called Santa Fé de Bogotá, is the capital, and largest city, of Colombia. It is also designated by the national constitution as the capital of the department of Cundinamarca, even though the city of Bogotá now comprises an independent Capital district...

     35,000 - 40,000


Many BRT systems, such as Ottawa's OC Transpo and Brisbane's South-East Busway
South-East Busway, Brisbane
The South East Busway is a grade separated bus-only corridor running south from the Brisbane CBD to Eight Mile Plains, in South East Queensland. Service providers using the Busway operate under the TransLink system...

, are based on multiple bus routes sharing a common dedicated busway to bypass congestion, especially to/from a central business district
Central business district
A central business district is the commercial and often geographic heart of a city. In North America this part of a city is commonly referred to as "downtown" or "city center"...

. In this form, the BRT system's passenger capacity is limited by vehicle capacity multiplied by vehicle headway of the busway. As buses can operate at headways as low as 10 seconds between vehicles (compared to at least one minute headways for rail vehicles), actual busway capacity can reach passenger rail capacities. In the NBRTI's May 2006 report, average headways of 13 seconds at busy intersections were observed in the TransMilenio BRT system.

At the high end of capacity, the Lincoln Tunnel
Lincoln Tunnel
The Lincoln Tunnel is a long tunnel under the Hudson River, connecting Weehawken, New Jersey and the borough of Manhattan in New York City.-History:...

 XBL bus lane
Bus lane
A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport that would be otherwise held up by traffic congestion...

 between New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

 and New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 carries 62,000 pph in the 4-hour morning peak, more than any light rail line. However, this lane serves no intermediate stops, and normally runs without any interruption in flow. Furthermore, a very large multi-story terminal station (Port Authority Bus Terminal
Port Authority Bus Terminal
The Port Authority Bus Terminal is the main gateway for interstate buses into Manhattan in New York City...

) is required to accept and dispatch passengers in hundreds of buses. Intermediate stops increase the headway, and limit a BRT lane to about 10,000 pph, even with passing lanes in the stations. This is still five times the number carried in the automobiles of a congested freeway lane. At its busiest point, Brisbane's South-East Busway currently has the capacity for in excess of 15,000 pph per direction.

Many agencies make a clear distinction between a pure BRT, which operates in exclusive lanes, and a more compromised form in mixed traffic. For example, the Los Angeles Orange Line
LACMTA Orange Line
The Orange Line is one of two lines on the Metro Liner bus rapid transit network in Los Angeles County, California. It operates between Warner Center in the Woodland Hills and the North Hollywood Metro Station in the San Fernando Valley where it connects with the Red Line on the Metro Rail light...

 runs entirely in an exclusive lane and therefore achieves speed and reliability comparable to rail. Because it is functionally equivalent to rail, the Los Angeles County Metropolitan Transportation Authority presents this line as an integral part of its rail transit system, distinct from its "Rapid
Metro Rapid
Metro Rapid is a bus rapid transit service in Los Angeles County, California that operates in mixed traffic environments and has fewer stops than the Metro Local service. The system is mainly operated by LACMTA. Two routes are operated by Santa Monica Transit and one by Culver City Transit...

" lines, which run in mixed traffic.

Cost

The capital costs of implementing BRT lines can be lower than up-front costs of constructing LRT lines. A study by the United States Government Accountability Office
Government Accountability Office
The Government Accountability Office is the audit, evaluation, and investigative arm of the United States Congress. It is located in the legislative branch of the United States government.-History:...

 found that the average capital cost per mile for busways was $13.5 million while light rail average costs were $34.8 million. However, a huge range of capital costs can be seen, as BRT lines can cost anywhere from $200,000—$55 million per mile, while LRT lines can range from $12.4—$118.8 million per mile. The total investment varies considerably due to factors such as cost of the roadway, station structures, park-and-ride facilities, traffic signal systems and vehicles.

Environmental problems

The typical diesel engine on the bus causes noticeable levels of air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....

, noise
Noise
In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...

 and vibration. With hybrid vehicles and the new forms of trolleybus
Trolleybus
A trolleybus is an electric bus that draws its electricity from overhead wires using spring-loaded trolley poles. Two wires and poles are required to complete the electrical circuit...

, BRT designers hope to increase ride quality and decrease pollution. Since the energy used for acceleration is proportional to the vehicle mass, electric traction allows lighter vehicles, faster acceleration, and ability to feed energy back into batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

 or the power grid through regenerative brakes. Regenerative braking has also become standard on many modern rail systems.

A BRT system can use trolleybuses to lower gaseous and noise emissions. The price penalty of installing overhead lines
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

 could be offset by the system's environmental benefits potential for savings from centrally generated electricity, especially in cities where electricity is less expensive than other power sources. In addition, most trolleybus applications can be converted to light rail with the only extra expense being the laying and maintenance of tram tracks in the street.

In tunnels or tunnel systems

A special issue arises in the use of bus vehicles in metro transit
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...

 structures. Since the areas where the demand for an exclusive bus right-of-way are apt to be in dense downtown areas where an above-ground structure may be unacceptable on historic, logistic, or environmental grounds, use of BRT in fully underground tunnels may not be avoidable.

Since buses are usually powered by internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

s, bus metros raise ventilation issues similar to those of tunnel
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...

s. In the case of tunnels, powerful fans typically exchange air through ventilation structures on the surface, but are usually placed in a location as remote as possible from occupied areas to minimize the effects of noise and concentrated pollution.

A straightforward way to deal with this is to use internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

s with lower emissions. The 2008 Euro V European emission standards
European emission standards
European emission standards define the acceptable limits for exhaust emissions of new vehicles sold in EU member states. The emission standards are defined in a series of European Union directives staging the progressive introduction of increasingly stringent standards.Currently, emissions of...

 set a limit on carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...

 from heavy-duty diesel engines of 1.5 g/kWh. This is one third that of the 1992 Euro I standard. As a result, less forced ventilation will be required in tunnels to achieve the same air quality.

A more complex alternative is electrical propulsion in tunnels. Seattle in its Metro Bus Tunnel
Metro Bus Tunnel (Seattle)
The Downtown Seattle Transit Tunnel, also referred to as the Metro Bus Tunnel, is a public transit tunnel that runs the length of downtown Seattle, from 9th Avenue and Pike Street to 5th Avenue S. and S. Jackson Street. Approved by Metro Transit in 1983, construction began in 1987. It was...

, and Boston
Boston
Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...

 in Phase II of its Silver Line
Silver Line (MBTA)
The Silver Line is the only bus rapid transit line currently operated by the Massachusetts Bay Transportation Authority . It operates in two sections; the first runs from Dudley Square in Roxbury to downtown Boston, Massachusetts and South Station, mostly via Washington Street, with buses...

 are using this method in their BRTs. In the case of Seattle, dual-mode
Dual-mode bus
A dual-mode bus is a bus that can run independently on power from two different sources, typically electricity from overhead lines or batteries, alternated with conventional fossil fuel ....

 (electric/diesel electric) buses manufactured by Breda were used until 2004, with the center axle driven by electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...

s obtaining power from a trolley wire
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...

 through a trolley pole
Trolley pole
A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" overhead wire to the control and propulsion equipment of a tram or trolley bus. The use of overhead wire in a system of current collection is reputed to be the 1880 invention of Frank J....

 in the subway, and with the rear axle driven by a conventional diesel
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 powertrain
Powertrain
In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...

 on freeways and streets. Boston is using a similar approach, after initially using electric trolleybuses to provide service pending delivery of the dual-mode vehicles in 2005. In 2004, Seattle replaced its "Transit Tunnel" fleet with diesel-electric hybrid buses, which operate similarly to hybrid cars outside the tunnel and in a low-noise, low-emissions "hush mode" (in which the diesel engine operates but does not exceed idle speed) when underground.

The need to provide electric power in these underground environments brings the capital and maintenance costs of such routes closer to those of light rail, and raises the question of building light rail instead. In Seattle, the downtown transit tunnel was retrofitted for conversion to a shared hybrid-bus and light-rail facility in preparation for Seattle's Central Link Light Rail
Link Light Rail
Sound Transit Link Light Rail is a rapid transit project in the Greater Seattle region, originally approved by a ballot measure in November 1996. Two lines are currently operating as of 2009: Tacoma Link, which uses 3 vehicles built by Škoda, and Central Link, which uses 35 vehicles built by Kinki...

 line, which opened in July 2009.

Think Tanks and Blogs

In the USA there are at least three think-tanks directly involved in lobbying for BRT systems:
  • National Bus Rapid Transit Institute (NBRTI) — established by the US Federal Government in January 1991, and housed at the Center for Urban Transportation Research (CUTR) at the University of South Florida
    University of South Florida
    The University of South Florida, also known as USF, is a member institution of the State University System of Florida, one of the state's three flagship universities for public research, and is located in Tampa, Florida, USA...

  • Bus Rapid Transit Policy Center (BRTPC) — promotes BRT technology over light rail
  • Institute for Transportation and Development Policy
    Institute for Transportation and Development Policy
    The Institute for Transportation and Development Policy is a US-based non-governmental non-profit organization providing technical assistance to cities and local advocacy groups on sustainable transportation development throughout Asia, Africa, and the Americas...

     (ITDP) — a non-governmental organization focussed on promoting BRT systems in developing countries


The objectivity of the work of CUTR and at least one of its employees has been questioned.

EMBARQ
EMBARQ - The WRI Center for Sustainable Transport
EMBARQ - The WRI Center for Sustainable Transport works with cities in the developing world to catalyze and help implement sustainable solutions to problems of urban mobility....

, The World Resources Institute
World Resources Institute
The World Resources Institute is an environmental think tank founded in 1982 based in Washington, D.C. in the United States.WRI is an independent, non-partisan and nonprofit organization with a staff of more than 100 scientists, economists, policy experts, business analysts, statistical analysts,...

's Center for Sustainable Transport supports the development of BRT and often posts news related to BRT on the TheCityFix blog network.

The Streetsblog series of blogs and Streetfilms videoblog also are frequent proponents of BRT.

Bus Rapid Transit Planning Guide

In June 2007, the Institute for Transportation and Development Policy (ITDP)
Institute for Transportation and Development Policy
The Institute for Transportation and Development Policy is a US-based non-governmental non-profit organization providing technical assistance to cities and local advocacy groups on sustainable transportation development throughout Asia, Africa, and the Americas...

 published the BRT Planning Guide with support from the United Nations Environment Programme
United Nations Environment Programme
The United Nations Environment Programme coordinates United Nations environmental activities, assisting developing countries in implementing environmentally sound policies and practices. It was founded as a result of the United Nations Conference on the Human Environment in June 1972 and has its...

, the Deutsche Gesellschaft für Internationale Zusammenarbeit, the Hewlett Foundation, and Viva Cities. The guide draws from the extensive BRT design experience of Latin America
Latin America
Latin America is a region of the Americas where Romance languages  – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...

n transit planners, and aims to disseminate this information in cities looking to design and implement BRT systems of their own. The guide is currently available in English, Spanish, Portuguese, and Chinese, and is free for download in .pdf format from ITDP's
Institute for Transportation and Development Policy
The Institute for Transportation and Development Policy is a US-based non-governmental non-profit organization providing technical assistance to cities and local advocacy groups on sustainable transportation development throughout Asia, Africa, and the Americas...

 website.

Characteristics of Bus Rapid Transit

In the U.S.A., a report “Characteristics of Bus Rapid Transit for Decision-Making” (CBRT) was prepared by the National Bus Rapid Transit Institute located at the Center for Urban Transportation Research. It provides transportation planners and decision-makers with basic information and data to support the development and evaluation of bus rapid transit (BRT) concepts. This report describes the physical, operational, cost, performance and potential benefits of BRT's.

See also

  • Express bus service
  • Quality Bus Corridor
    Quality Bus Corridor
    Quality Bus Corridors are an initiative to give dedicated road space and traffic signal priority to buses in Dublin, Ireland in order to reduce journey times and improve service consistency. The aim of the initiative is to encourage people to change from cars to buses and thus reduce traffic...

  • Queue jump
    Queue jump
    A queue jump is a type of roadway geometry typically found in bus rapid transit systems. It consists of an additional travel lane on the approach to a signalised intersection. This lane is often restricted to transit vehicles only, though some variations may permit bicyclists, mopeds, and/or...

  • Straddling bus

  • Sustainable transportation
  • Transit bus
    Transit bus
    A transit bus , also known as a commuter bus, city bus, or public bus, is a bus used for short-distance public transport purposes...

  • Traffic engineering (transportation)
    Traffic engineering (transportation)
    For the engineering of communications and computer networks, see Teletraffic engineering.Traffic engineering is a branch of civil engineering that uses engineering techniques to achieve the safe and efficient movement of people and goods on roadways...



External links


Country specific
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