Addison Lee has unveiled plans to launch self-driving taxis in London by 2021 as it joins the autonomous vehicle road race.

The firm has formed a strategic alliance with ground transportation business Oxbotica, which specialises in self-driving vehicle software.

Together, the duo will create digital maps of more than 250,000 miles of public roads in and around the capital, pinpointing the position of every kerb, road sign, landmark and traffic light in preparation for the deployment of autonomous cars.

Addison boss Andy Boland said: “Urban transport will change beyond recognition in the next 10 years with the introduction of self-driving services, and we intend to be at the very forefront of this change by acting now.

“Autonomous technology holds the key to many of the challenges we face in transport. By providing ride-sharing services, we can help address congestion, free space used for parking and improve urban air quality through zero-emission vehicles.”

Addison Lee’s long term aim is to take a slice of the expanding car services market for connected autonomous vehicle technology, which is forecast to be worth £28 billion in the UK by 2035.

Chancellor Philip Hammond has thrown his weight behind autonomous cars, saying that he wants “genuine driverless vehicles” on Britain’s roads, also by 2021.

To this end, the Government has tasked the Law Commission with carrying out a detailed review of driving laws to ensure the UK is at the forefront of the sector.

Addison rival Uber and several other firms are also gearing up to roll out driverless cars, pending safety and regulatory permissions.

But the news comes at a challenging time for Addison Lee, which swung to a loss last year after it was stung by investment and acquisition costs.

The group posted a pre-tax loss of £20.8 million in the year to August 2017, compared to a profit of £10.5 million the year before.

Addison put the fall down to “intense long-term investment”, acquisition integration and reorganisation, which culminated in £18.6 million of exceptional costs.

The taxi firm has been looking to keep pace with the astronomical rise of Uber, which has radically shaken up the industry with its ride-hailing smartphone app.

As part of these efforts, Addison has expanded rapidly into the US, snapping up rival Flyte Tyme as well as boosting its global footprint by buying Tristar Worldwide, which has operations in 80 countries.

Addison Lee, which is owned by US private equity firm Carlyle Group, was founded in Battersea in 1975 and has grown to become Europe’s largest private hire car service company, carrying out 10 million journeys per year.