The Obama administration is hoping to accelerate testing of fully autonomous vehicles in the US by creating a “consistent national policy”, threatening to override a patchwork of state rules around driverless cars. The US secretary of transportation, Anthony Foxx, told the Detroit Auto Show on Thursday that it would propose new principles of “safe operation for fully autonomous vehicles” within six months, urging a more ambitious timetable for introducing driverless cars than has been proposed by individual states. State rules, such as those proposed in California last month, have restricted testing of fully autonomous vehicles on public roads for at least three years, angering the likes of Google. Mr Foxx said that more widespread testing was required to gather data that could establish the technology’s safety benefits. “We are on the cusp of a new era in automotive technology with enormous potential to save lives, reduce greenhouse gas emissions, and transform mobility for the American people,” said Mr Foxx. President Barack Obama will propose that $4bn be allocated from the 2017 budget for autonomous driving and vehicle safety technology over 10 years, he added.