A Government report has warned that motorists could be stuck in congestion for nearly twice as long compared to current levels if self-driving cars become commonplace.

Department for Transport (DfT) traffic projections for England and Wales show delays may rise by up to 85% from 2025 to 2060 in that scenario.

This data is based on connected and autonomous vehicles making up half of the vehicles on the road by 2047.

This would lead to more traffic by “increasing the mobility of the elderly and those who do not currently hold a driving licence”, according to the report.

But the document, published last month, claims “the ability to work or relax while travelling in a self-driving car” means occupants will be “more amenable to sitting in traffic”.

The Argus: The report states that congestion will increase as it will allow elderly people and those who don't currently hold licenses to go on the roadsThe report states that congestion will increase as it will allow elderly people and those who don't currently hold licenses to go on the roads (Image: Aaron Chown/PA)

RAC Foundation director Steve Gooding told the PA news agency: “There are currently 5.9 million licence holders aged 70 or over in Britain, so we know the demand for mobility is there among those of a senior age.

“In the foreseeable future, automated vehicles offer the tantalising prospect of independence for the many millions more people who fall into the older age group but for whatever reason – cost, medical impairment – don’t currently drive.”

Mr Gooding predicted that the way in which autonomous technology is deployed will be significant.

He said: “If everyone insists on having their own driverless car then traffic volume and parking pressures will rise.

“However, if we are prepared to access these vehicles on-demand and forego personal ownership then we could have a win-win situation: quieter roads, fewer cars shared by the many, and cheaper transport.”

The research was not welcomed by self-driving firm Wayve which was critical of the modelling used.

Kaity Fischer, its vice president of commercial, said: “Self-driving vehicles will be an integral part of a safer, more efficient and more sustainable transport system.

“The Government’s modelling was based on the private ownership of self-driving cars, but here at Wayve we are optimising our technology on electric vehicles for fleet customers in sectors like last-mile delivery and shared mobility services.

“Self-driving vehicles, when used in electric fleets, will ultimately lead to faster journey times and reduce the number of vehicles on the road, cutting congestion and emissions.”

When will self-driving cars start being seen on roads?

Fully driverless cars are not legally permitted in the UK but autonomous features are being developed by car makers.

Oxford-based technology company Oxbotica completed its first fully autonomous, driverless vehicle test on public roads in May 2022.

In August last year the DfT said it expected self-driving vehicles to be available for use by 2025.