It consists of 21 vehicles operating on a 3.9-kilometre (2.4 mi) route connecting Terminal 5 to its business passenger car park, just north of the airport.

[3] To reduce construction costs, Ultra largely uses off-the-shelf technologies, such as rubber tyres running on an open guideway.

Recently, the company renamed itself to "Ultra PRT Limited" because of its primary business, and it moved its corporate headquarters to Bristol.

Personal rapid transit was originally developed in the 1950s as a response to the need to move commuters in areas with densities too low to pay for the construction of a conventional metro system.

Smaller towns and cities that could never hope to fund a conventional mass transit system could afford PRT, and the concept generated intense interest.

Numerous PRT systems were designed in the late 1960s and early 1970s, many as a result of the publication of the highly-influential HUD reports.

In general, the systems intended to use small four-to-six-passenger vehicles, but most evolved to larger designs over time (see Alden staRRcar).

Another change is the moving of the guidance logic from centralised computers to on-board systems of dramatically improved performance, allowing the vehicles to steer and switch themselves between routes on their own.

Together, the changes mean the vehicle no longer needs strong mechanical contact with the guideway, which can be dramatically reduced in complexity.

In the case of Ultra, the guideway can consist of as little as two parallel rows of concrete barriers, similar to the bumpers found in a car park.

As a result, the trackway is similar in complexity to a conventional road surface, a light-duty one as the vehicles will not vary in weight to the extent of a tractor-trailer.

Even the stations are greatly simplified; in the case of ground-level tracks, the lack of any substantial infrastructure means that the vehicles can stop at any kerb.

According to Ultra, its control system has three separate levels of operation, with the following features: The 1 kilometre (0.62 mi) test track in Cardiff was launched in January 2002.

The line is largely elevated, but it includes a ground-level section, where the route passes under the approach to the airport's northern runway.

The system will include 6 miles (9.7 km) of guideway, 4 stations, 22 pods and will connect a remote parking area to the two terminal buildings.

The second is a Group Rapid Transit (GRT) with thirty seat vehicles running mainly at grade with ground level stations.

[26] In March 2010, the government of Haryana said that it was looking into a proposal to deploy Ultra for rapid commuter transport in the city of Gurugram.

[27] In July 2012, it was reported that the Chief Minister of Haryana had ordered officials to "complete all the necessary formalities in the next three months and begin work on the project".

[28] In October 2016, Indian Transport Minister Nitin Gadkari said four competing technical proposals had been received, and the system was still subject to approval and financial bidding.

[29] In January 2017, ULTra was one of three companies – along with SkyTran and Metrino – approved to build a test track evaluate PRT technology for potential deployment in Gurugram and Bengaluru.

[15] In December 2011, Ultra-Fairwood (a joint venture) announced a plan to build an 8-kilometre (5.0 mi) elevated guideway in a Y-shaped network in Amritsar, India, serving seven stations, with over 200 pods.