Cabinentaxi, sometimes Cabintaxi in English, was a German people mover development project undertaken by Demag and Messerschmitt-Bölkow-Blohm with funding and support from the Bundesministerium für Forschung und Technologie (BMFT, the German Ministry of Research and Development).U.S. Congress, Office of Technology Assessment, "Impact of Advanced Group Rapid Transit Technology", January 1980, pg. 46 Cabinentaxi was designed to offer low-cost mass transit services where conventional systems, like a metro, would be too expensive to deploy due to low ridership or high capital costs.
Cabinentaxi systems could be operated in a variety of fashions depending on the need. It is most widely known as the first true personal rapid transit (PRT) system, where customers call up a small "car" on demand which then takes them directly to their destination without any stops along the way. The system could also be used in a group rapid transit (GRT) fashion, using larger cars with up to 18 passengers. In this case the vehicles would travel along a fixed route, stopping at any station that a passenger requested. Cabinentaxi could also mix the two modes on a single line, which allowed direct routing to high-density areas when traffic loads were low, saving the larger van-like vehicles for the high-demand periods.
Cabinentaxi was in serious consideration for two deployments in the late 1970s; BMFT was in the process of funding a deployment in Hamburg while their U.S. counterpart, the Urban Mass Transit Authority (UMTA), selected it as a front-runner for a deployment in Detroit. Cabinentaxi's corporate partners decided to pull out of the Detroit competition to focus on the Hamburg development. When unrelated budget cuts drained the BMFT's coffers, the Hamburg project was also canceled, and the Cabintaxi Joint Venture gave up on the public transit field and withdrew the Cabintaxi technology from the market. The rights were purchased in 1985 by a small U.S. consortium, Cabintaxi Corporation, but no developments have followed. The only commercial use was a modified system, the Cabinlift, which operated as a horizontal elevator between buildings at the Schwalmstadt-Ziegenhain hospital in Germany until 2002.
History
Background In the early 1950s, urban planner Donn Fichter started work on a book that would eventually emerge in 1964 as Individualized Automatic Transit and the City.Donn Fichter, "Individualized Automatic Transit and the City", BH Sikes, 1964 Fitcher argued that the only way to solve the gridlock problems in cities being caused by increased car ownership was to use mass transit systems. Fichter argued that unless the systems operated more like a taxi service, arriving when called for and taking the passenger directly to their destination, people would not leave their cars to use it. Busses and metro systems are not personalized, they run on pre-planned routes and schedules, making stops along the way that do not serve each individual, only the group of riders as a whole.
Fichter and other planners tapped into a zeitgeist that was being fuelled by rapid urban decay in the U.S. President Kennedy addressed congress in 1962 and stated that "To conserve and enhance values in existing urban areas is essential. But at least as important are steps to promote economic efficiency and livability in areas of future development. Our national welfare therefore requires the provision of good urban transportation, with the properly balanced use of private vehicles and modern mass transport to help shape as well as serve urban growth."FTA, "The Beginnings of Federal Assistance for Public Transportation" Funding provided through the U.S. Department of Housing and Urban Development (HUD) led to a series of reports by a variety of aerospace firms (notably Aerospace Corporation), today known as the "HUD reports", that explored various concepts and provided strong support for the basic concepts. A follow-on bill later in the decade provided additional funding for development of several experimental systems, and created the Urban Mass Transit Administration (UMTA).
Spectrum of designs Other companies and government organizations soon joined these efforts, as it appeared PRT systems would soon be being deployed around the world. By the early 1970s there were at least a dozen development efforts in the U.S., a similar number in Europe and Japan, and two in Canada. The systems differed considerably in operating concept.
On the "simple end" of the scale were vehicles that used a guideway to steer, and left most other operations to a centralized control centre with some form of automatic train control. These systems had fairly slow reaction times that demanded fairly long headways between the trains. Most conventional metros have headways around two minutes or more, these new systems were generally on the order of 30 seconds. To make these systems efficient at high demand levels they had to have fairly large capacities, on the order of 25 to 100 passengers, which places them in the group rapid transit, or GRT, end of the people mover spectrum. These sorts of systems can be simplified if high performance is not required; GRT systems are quite common at airports today.
On the other end of the scale were the personal rapid transit systems, or PRTs. These systems abandoned centralized control for a simpler distributed solution based on set timings, speeds, or flocking behaviour. By placing the headway logic on the vehicles the reaction timing was dramatically improved, because they no longer had to communicate with a centralized system for traffic information or instructions. PRTs generally worked on headways of less than 10 seconds, which greatly increased the passenger density of the system as a whole. This allowed the vehicles to be much smaller and still retain the same system capacity as the larger GRTs, while offering the sort of personalized car-like operations that Individualized Automatic Transit envisioned.
Cabinentaxi In 1969 Demag and MBB independently started projects studying PRT systems as a result of the HUD reports.J. Edward Anderson, "Some Lessons from the History of Personal Rapid Transit", Taxi2000, 4 August 1996 At the time, the Bundesministerium für Forschung und Technologie (BMFT) was involved in a wide variety of transport research, including a variety of maglev trains for high-speed service, several automated railway systems, as well as more mundane research in railway safety and signalling. Significant within the transportation development programs of the BMFT was the direct involvement of the VOV (German Association of Public Transit Operators), the Deutsche Bundesbahn (German Federal Railway) and their safety experts. This assured that when development was completed, the systems would meet German (and by extension international) public transit standards.
When the BMFT learned of the separate efforts at Demag and MBB, they urged both companies to combine their efforts under a new joint operating company,Hesse and Bendix which became Cabinentaxi. BMFT provided 80% of the total funding, considerably less than their counterparts in the U.S., which completely funded by the UMTA. By this time the system had been well-defined, and was committed to true PRT point-to-point service. In order to avoid stops along the way, stations were "off-line", on separate guideways placed beside the main routes, allowing en-route cars to pass them by. The cars themselves would handle switching along a pre-defined route, which allowed them to be directed to an optimal path in a network of any complexity. Studies suggested a three-passenger car for the basic system, although in order to increase capacity they also had cars with seating for 6, 12 and 18 passengers. These larger cars would normally be planned to operate in GRT fashion in order to increase the overall capacity of the network in the early development stages, where small networks in dense areas would not be meaningful in a small vehicle PRT mode. The larger cars could also be connected front-to-back to form two-car trains, further increasing capacity for some simple applications.
One problem with all elevated transportation system structures in general, is that the guideways (highways or transit) are widely considered to be an eyesore. In order to reduce the size of the guideways, Cabinentaxi took the uncommon approach of optionally allowing its cars to run on the top or bottom of a single track. The cars could not be switched from top to bottom, however. If this option was used, the guideways were supported on pillars that attached to the track from the side, rather than directly below. Cabinentaxi's guideway is noticeably smaller and thinner than conventional elevated systems, like the Vancouver SkyTrain. The track is approximately six feet wide, slightly smaller than a row of parking spots on the side of a city street.
Prototypes and testing Testing of the motor and control systems started in 1972 on a 13-meter closed-loop track, running for 18 months. This was followed in August 1973 by a 150 meter test track and three 3-passenger vehicles installed near Hagen, Germany. The test track was expanded several times. By October 1974 it was 1136 meters long and featured two passenger stations with a closed-loop track, adding two additional vehicles for a total of five. By 1975 it had three stations and nine vehicles. The first 12-person vehicle was introduced that October. The final expansion was completed in 1976, bringing the total track to 1.9 km with six stations and twenty-four vehicles. In 1975, Raytheon Missile Systems examined the prototype system and decided to license it for deployment in the U.S., but a final agreement was never reached.
Cabinentaxi technology logged over 400,000 vehicle-miles between 1975 and 1978 on the Hagen test track. In 1977 the system completed fleet operation endurance testing of 7500 continuous vehicle hours, extending that in 1978 to 10,000 continuous vehicle hours. These are the only PRT fleet endurance test of these magnitudes ever carried out. Headways were reduced throughout the period, vehicle separations started at under 3 seconds, reaching 1.9 seconds in later tests, about the same as cars on a highway. The basic operating speed was also increased during testing, from the original 30 km/h to 36 in the later tests, with options for even higher speeds in production versions.
Late in the program a number of safety studies were carried out. Fire was a major concern of safety officials, but due to the simplicity of the vehicles, and a fire safety risk-reduction program it was demonstrated the possibility of fire was reduced to a non-issue. Other problems, like broken motors or a widespread power failure that demanded evacuation, were the primary areas of concern, but the solutions were found to lie in ground-based equipment and in specially equipped rescue cars that could operate on the guideway and access both levels. The final system plans required no external walkways.
Cabinlift While work on the basic Cabinentaxi continued, a modified version known as Cabinlift was also developed. Originally designed for installations in healthcare facilities, Cabinlift was based on substantially similar technology as the basic Cabinentaxi. The Cabinlift cars were larger and taller, allowing easy walk-on access for passengers and bulky loads, notably wheeled hospital beds and gurneys. The cars could be built with the doors on the side, or on the ends. Unlike Cabinentaxi, passengers in Cabinlift could stand with some fold-down seats available.