Guided bus

From Wikipedia, the free encyclopedia

(Redirected from Guided busway)
Jump to: navigation, search
A bus on the O-Bahn Busway route in Adelaide.
A bus on the O-Bahn Busway route in Adelaide.

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 all other traffic, permitting the maintenance of reliable schedules on heavily used corridors even during rush hours.

Guidance systems can be either physical, such as kerbs, or remote, such as optical or radio guidance.

On kerb-guided buses (often abbreviated to KGB) small guide wheels are attached to the bus, and these engage vertical kerbs on either side of the trackway. The bus is steered in the normal way away from the guideway. The start of the guideway is funnelled from a wide track to the normal width. The trackway allows for high-speed operation on a narrow guideway as well as precise positioning at boarding platforms, facilitating access for the elderly and disabled.

Contents

Only a few examples currently exist, but more are proposed in various countries. The longest guided busway in the world is the O-Bahn Busway route in Adelaide, South Australia, which has been operating reasonably successfully since the mid 1980s.

The first guided busway in United Kingdom was in Birmingham, branded as Tracline 65 and had a short 600 metre length as an experiment in 1984. It has since been removed.[1] A number of guided busways have since been built or are planned in the United Kingdom, see List of guided busways and BRT systems in the United Kingdom.

In Mannheim, Germany from May 1992 to September 2005 a guided busway shared the tram alignment for a few hundred metres, which allowed buses to avoid a congested stretch of road in a location where there was no space for an extra traffic lane. It was discontinued as the majority of buses fitted with guide wheels were withdrawn for age reasons. There are no plans to convert newer buses.

Nagoya Guideway Bus in Nagoya, Japan, opened in March 2001, and is the only guided bus line in the country.

Diagram of the Translohr central guide rail (green) and the vehicle's guide wheels (red), which grasp the rail perpendicular to each other, thereby all but eliminating derailments.
Diagram of the Translohr central guide rail (green) and the vehicle's guide wheels (red), which grasp the rail perpendicular to each other, thereby all but eliminating derailments.
Cross section of guide rail and guide wheel of Bombardier's GLT
Cross section of guide rail and guide wheel of Bombardier's GLT

A further development of the guided bus is the "tramway on tyres", a rubber-tyred vehicle guided by a fixed rail in the ground, which draws current from overhead electric wires like a conventional tram.

Two incompatible systems exist, the Guided Light Transit designed by Bombardier Transportation, and the Translohr system. There are no guide bars on the sides but there is a central guidance rail that, in the case of Translohr, is a special rail that is grasped by a pair of metal guide wheels set at 45° to the road and at 90° to each other. In the Bombardier system a single double flanged wheel between the rubber tires follows the guidance rail. This is why the two systems are not compatible, however the shape of the groove of the double-flanged Bombardier guide wheel could possibly be adapted to the shape of the top of the Translohr guidance rail. In both cases the weight of the vehicle is borne by rubber tyres on bogies to which the guide wheels are attached. Power is supplied by overhead lines, or by rechargeable batteries in areas where there are no overhead wires.

The Bombardier system has been adopted in Nancy and Caen, France, while the Translohr system is in use in Clermont-Ferrand, France, and Tianjin, China, and is under construction in Padua, L'Aquila, and the mainland Mestre district of Venice in Italy. The Translohr system is intended for guidance-only operation, while the Bombardier system can be driven as a normal bus as requirements dictate, such as journeys to the depot. The Bombardier vehicles are legally considered buses, and must bear bus-like rear-view mirrors, lights and number plates. Unlike trams, GLT vehicles have a steering wheel, though it is not used when following the guidance rail. Because the Translohr "tram" cannot move without guidance it will probably not be classified as a bus. Hence the Translohr vehicles that on test runs on the Clermont-Ferrand network are not equipped with licence plates.

A Translohr rubber-tyred "tram" for the future system in Padua, Italy
A Translohr rubber-tyred "tram" for the future system in Padua, Italy

These systems offer a much more tram-like experience than a regular guided bus, and offer some advantages over trams, such as a potentially smaller turning radius, the ability to climb steeper gradients (up to 13%), and quieter running around corners. The infrastructure installation can be less complicated than the installation of a complete tram line in an existing street. These systems have been likened to the tram equivalent of rubber-tired metros, and they are also correspondingly less efficient than steel-wheeled light rail vehicles. On the negative side, there have been significant technical difficulties in Nancy since the system opened with "derailments", where the guidance system becomes detached from the central guide rail.[2]

Some commentators believe that rubber-tyred "trams" share the same problems of negative perception as other bus rapid transit systems.

Other experimental bus systems have non-physical guidance systems, such as sensors or magnets buried in the roadway.[3] In 2004, Stagecoach Group signed a deal with Siemens AG to develop an optical guidance system for use in the UK.[4]

Wikimedia Commons has media related to:


Types of buses
Articulated busDouble-decker bus - Dual-mode busGuided busGyrobusLow-floor busMidibusMinibus
MotorcoachParty busSchool bus - Transit busTrolleybus
Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.