The so-called ‘CarTube’ would integrate the existing motorways in large cities into a network of small underground tunnels.

Automatic cars would be controlled by a ‘platoon system’, whereby they would travel in groups controlled using artificial intelligence. The method allows cars to travel closer to one another since the distance needed for human reaction is eliminated, increasing the tunnels’ capacity.

The practice claims the network would double transport capacity for the same investment as conventional mass transport and reduce travel time by 75 per cent. It said cars would travel at a steady speed of 50mph and a journey from Heathrow to the City would take 14 minutes.


PLP director of research Lars Hesselgren said the concept was a ‘direct response’ to mass transit and traffic congestion in the world’s largest cities. ‘CarTube has the potential to be the next best thing to teleportation,’ he said. ‘It will revolutionise existing cities and allow for unprecedented urban forms.’

Users would be able to book a trip on the CarTube using an app on their smartphones, which would calculate a fare and estimated arrival time.

The concept has been created by PLP’s research arm, which supports the practice’s design teams as an independent think-tank. It recently developed a project with Cambridge University for an 80-storey wooden skyscraper rising from London’s Barbican complex.

PLP said it was currently in discussions with a range of partners about funding for the CarTube.