UK's first driverless bus service showcased crossing Forth Road Bridge ahead of passenger launch on Monday

Autonomous buses were shown off on the Forth Road Bridge on Thursday ahead of going into passenger service in the most complex test of the technology anywhere in the world.

The first fare-paying passengers will be able to use the ground-breaking vehicles on a 14-mile route between the Ferrytoll park and ride near the Forth Road Bridge and Edinburgh Park from Monday.

A “safety driver” will remain at the wheel but most of the route via the bridge and the M90, M9 and M8 motorways will be operated in autonomous mode, with computers on the bus controlling the speed and steering, and applying the brakes if needed. Passengers will be advised to wear seat belts, but operator Stagecoach said that was no different to its other buses which were fitted with them.

The CAVForth – Connected and Autonomous Vehicles Forth – trial will continue until 2025 and is Britain’s first full-size autonomous bus operation. Fusion Processing, which is responsible for the technology involved, said the route was “by far the most complex and ambitious in the world”.

Stagecoach said a second member of staff – a “bus captain” – would be aboard to help passengers get on and off, sell tickets and answer queries.

The Perth-based bus firm said it eventually expected to be able to dispense with the safety driver, but the bus captain would remain on board to take over in an emergency. It said that would speed up passenger boarding and alighting by ending the need for them to buy tickets or show passes as they boarded, which could cut journey times.

The trial, which will run until 2025, aims to demonstrate autonomous technology in a real-world environment transporting up to 10,000 passengers per week. A fleet of five vehicles will cover the route, in mixed traffic, at up to 50mph .

Kevin Stewart, Scottish Transport Minister, said: “It is really exciting to see the innovative and ambitious CAVForth Project take to the roads in earnest. We want Scotland to continue to be at the forefront in the development of Connected and Autonomous Vehicles and the start of this live trial will really help the country establish its credentials on the world stage.