The U.K. government has announced it’s working on a process to support so-called “advanced trials” of autonomous vehicles — i.e. trials without human safety drivers.

It also says it will be beefing up the existing Code of Practice for testing driverless cars to provide a framework to support the evolution of the tech, saying it’s on track to meet its goal of fully driverless cars being tested on public roads by 2021.

Commenting in a statement, Richard Harrington, automotive minister, said: “We want to ensure through the Industrial Strategy Future of Mobility Grand Challenge that we build on this success and strength to ensure we are home to development and manufacture of the next generation of vehicles.

“We need to ensure we take the public with us as we move towards having self-driving cars on our roads by 2021. The update to the Code of Practice will provide clearer guidance to those looking to carry out trials on public roads.”

The government gave the green light for hands-free testing of driverless cars back in 2015, though it still requires there to be a (human) safety driver behind the wheel (which also, of course, requires the vehicle to have a wheel in the first place).

The move was quickly followed by a Code of Practice for testing autonomous vehicles in public places — which remains in operation. But a Department for Transport spokesman said there’s been an increase in trial activity across the U.K. since then.

Hence the plan to update and strengthen the code and also make provisions for fully autonomous trials — to “set even clearer expectations for safe and responsible trials,” as the government’s press release puts it.

The current code of practice allows for automated vehicle trials on any U.K. road in compliance with U.K. law — which means test vehicles must include a remote driver.

But in the coming years the government is preparing to drop that requirement.

In its stead, it says the updated code will include an expectation on those carrying out trials to publish safety information; trial performance reports; and to carry out risks assessments before conducting a trial.

Trialing organisations will also be expected to inform the relevant authorities, emergency services and “anyone who might be affected by trial activity” — which could potentially entail a lot of outreach for autonomous vehicle startups hoping to run tests in densely populated urban environments. (Ergo, remote, rural regions may end up being test locations of initial choice.)

“Advanced trials will not be supported unless they have passed rigorous safety assessments,” the government also warns.

The devil will clearly be in the detail of the updated code and it’s not clear exactly when it will be published. Nor whether trials of fully autonomous vehicles will be able to take to public roads before 2021.

A report in today’s Times newspaper suggests such vehicles could be being tested by the end of this year. But the Department for Transport spokesman we spoke to would not confirm that time frame — pointing only to the existing government target of trials by 2021.