[1] 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.
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.
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.
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.
[2] 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.
"[3] 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).
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 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.
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.
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.
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 track is approximately six feet wide, slightly smaller than a row of parking spots on the side of a city street.
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.
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.
Additional lines would then be added until it was fully expanded with 138 km of track and 182 stations covering the majority of the city and several surrounding suburbs and towns.
[9] The developing firms found themselves without a market opportunity in Europe or the United States, and withdrew from the public transit field.
The vehicle bodies were made of aluminum over a steel chassis, riding on solid rubber wheels that engaged the guidance rails in the track.
[6] In order to provide fine control over vehicle spacing and reduce maintenance costs, the companies selected a linear motor (LIM) for the Cabinentaxi project.
Another advantage is that there is no contact between the motor and the track, so snow or rain will not affect its performance, which means a LIM vehicle does not require additional headspace in bad weather.
Stations had multiple berths for loading and unloading, as well as longer areas for acceleration and deceleration to collect vehicles as they switched on or off the main guideways.