A US traffic regulator has warned that one ‘mess up’ could set self-driving car technology back by decades as Google plans to test its own prototype over summer.

The acting head of America’s National Highway Traffic Safety Administration urged manufacturers like Google to work with the body to ensure they comply with current safety standards.

David Friedman’s comments at Bloomberg’s Next Big Thing summit in California yesterday came as British and Californian lawmakers plan to update traffic laws to legislate for driverless vehicles.

He said: "If anyone messes up the technology the first time, it can set the technology back for decades to come. It’s an exciting future, but also a future in which we need to move carefully and cautiously."

Google, Toyota and Nissan are all developing driverless cars, while Google has gone so far as to get rid of the steering wheel, accelerator and brake pedals in its own prototype, to be tested this summer.

Friedman said the highway regulator is hiring electrical engineers to help it understand the new software development, and warned that driverless cars won’t get rid of the element of human error, but rather shift it from the driver to the car’s designers or engineers.

The news comes a day after a UK Government minister said the Highway Code would be rewritten to legislate for self-driving cars in Britain.

Science minister David Willetts told the Daily Mail: "There is British technology, and it’s a lot cheaper than the Google technology. You need a regulatory regime so that these are permitted.

"What America is going to have is a legal regime in California that permits you to travel in one without requiring someone in the so-called driver’s seat."

California is expected to grant ‘driverless’ licenses from September, but Willetts said the Government will review the current law to "ensure there is a clear and appropriate regime for the testing of driverless cars that supports the world’s car companies to come hand test them here."