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Autonomous Alexander Dennis Enviro 200 AV for line over Forth Bridge near Edinburgh

Opening of the “BA 1” line

Almost exactly one year ago, on 15 May 2022, UTM reported that tests for an autonomous bus line from “Ferrytoll Park & Ride” in Fife to “Edinburgh Park Interchange” were now starting in Edinburgh, Scotland. In the meantime, the tests have been successful and therefore, exactly one year later to the day, on 15 May 2023, the corresponding connection will be officially opened under the line number “AB 1”. During the tests, more than 1,609,000 kilometres (1 million miles) were travelled with the five buses of the type “Alexander Dennis Enviro 200 AV” (with the car numbers 62001 to 62005) that Stagecoach procured for this line.

The first tests were already carried out in 2018: a prototype of the autonomous buses moved around the depot on its own, drove without a driver to refuel and to the car wash, and also drove to its parking place all by itself.

The opening of line “AB 1” with “full-grown” autonomous buses is running under the project name “CAVForth”. CAV stands for “Connected and Autonomous Vehicles”, and the Forth is the river that the line crosses on an impressive bridge. What is new about the line in Scotland is that “full-grown” buses are used here. In Germany, too, there have been and still are autonomous services, such as Line A 01 in Monheim (between Cologne and Düsseldorf) and the autonomous shuttle operated by the DB between the spa district and the railway station in Bad Birnbach in Lower Bavaria – but here minibuses for about ten passengers were and are used, such as the EasyMile EZ 10, the Navya Arma, the HEAT (in Hamburg), and from Araiv (ZF) and Holon. The latter two can already carry a little more passengers – and could also travel faster, if the legislator would let them.

What makes the difference, however, is that fact that large buses are now also driving autonomously in Edinburgh.

The partners at CAVForth speak of their project as one of the most ambitious and complex experiments with autonomous buses worldwide.    

The project partners

The six project partners at CAVForth are:

  • Fusion Processing Limited (project leader)
  • Stagecoach (as operator of the line)
  • Transport Scotland
  • Alexander Dennis (as manufacturer of the buses)
  • Edinburgh Napier University
  • Bristol Robotics Laboratory (software)

The project is funded by the UK Government’s Centre for Connected and Autonomous Vehicles.

The new line and its autonomous buses

The new Stagecoach line “AB 1” runs on schedule every 30 minutes, seven days a week. It is designed to carry 10,000 passengers per week. The line is 22.5 kilometres (14 miles) long and runs on the Forth Bridge, country roads, motorway, bus lanes and also on a private road. The line is 22.5 kilometres (14 miles) long and travels on the Forth Bridge, country roads, motorways, bus lanes and also on a private road. The buses are supposed to drive autonomously for 90 percent of the route, while the “operator”, who still has to be on board anyway for safety reasons, gets behind the wheel for the rest of the route. The buses “master” autonomous driving “Level 4”, which means that the bus is essentially autonomous, but an “operator” is still on board for safety. 

On the road, the buses have to cope with various complex traffic situations such as roundabouts, traffic lights and lane changes on the motorway. (Three years ago, when using a Navya Arma in Contern, Luxembourg, the author experienced that the “little one” on the way from the industrial area to the railway station was still overtaxed with a (multi-lane) roundabout, which is why the line ended before the roundabout – the last three hundred metres to the station on foot, please …).

The autonomous Alexander Dennis buses are approved for a speed of up to 80 km/h (50 miles), even though they travel in mixed traffic with other road users. 

Alexander Dennis has developed the buses from his normal Enviro 200, of which more than 8,000 are in use in the UK. That is why Alexander Dennis says this proven platform is well suited to the development of an autonomous system.

“Fusion Processing” ‘s role in the project team

Fusion Processing’s contributes its “CAV-Star” system as an “autonomous driving system”. This includes cameras, lidars, radar and artificial intelligence.  This will ensure, for example, that the bus travels at the optimal speed between two traffic lights in order to “swim along” optimally in the green wave. This avoids unnecessary braking and acceleration, brakes and tyres wear less, fewer particles are emitted …

Stagecoach has trained 20 drivers from its proven staff specifically for this autonomous line as “bus captains”. Such a “bus captain” does not have to stay at a fixed place in the car, he can walk around in the bus, for example to give passengers information or help them. “When passengers see,” says Stagecoach, “that this works and the computer takes care of the driving, they will have confidence in the system.”

Kevin Stewart, Scottish Transport Minister: “It’s really exciting to see the innovative and ambitious CAVForth project now on the road after all the hard work. Great to see this technology supporting our vision of sustainable, disability-friendly, safe and accessible transport.”

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All pictures: © Alexander Dennis