Just days after launching in the US, Tesla's Autopilot feature, which makes Model S cars autonomous on some roads, has arrived in the UK and Europe. According to Tesla boss Elon Musk, Japan is the only Tesla-selling country where the feature is yet to get regulatory approval.

Musk tweeted: "Regulatory approvals received, so Autopilot rolling out to all countries! (Excluding Japan, which is still under review)." Downloaded to all Model S cars built in the last 12 months, Autopilot is a free software update and makes use of hardware on the cars which was until now unused.

When asked if Autopilot hardware could be installed in older Model S vehicles, Musk said the amount of physical change needed was "enormous - like a spinal cord transplant, would cost less and work better with a new car".

The system takes control of the accelerator, brakes and steering on multi-lane roads like motorways, using the lane markers and surrounding traffic to stay in the right position and avoid accidents. Tesla says the software is still being developed and will be improved upon as it is used; it is currently a beta version and drivers have been advised to be alert with the steering wheel, and be ready to take control in case something goes wrong.

Next software update to improve how Autopilot learns

In a follow-up tweet, Musk said an update, called Autopilot 1.01, would be coming soon and include "curve speed adaption [sic], controller smoothness, better lane holding on poor roads, improved fleet learning". The new software will arrive as an over-the-air update, delivered via each Model S's 3G internet connection.

The Model S is the only car to have such a high level of autonomy on UK roads. But other manufacturers are keen to create their own self-driving features. In November, the new BMW 7-Series will gain a self-parking function, allowing it to park itself when no one is manning the car. The car is controlled by pressing a single button on the touch-screen key fob.

Although undeniably impressive, Autopilot has already been caught out by drivers using it incorrectly. A video published on YouTube (above) claims the system "tried to kill" its driver, having veered into oncoming traffic on a road on which it should not be used on. Another video shows the system being confused by a freeway slip road - another place, where its use is prohibited - and a third video shows a Tesla driving itself with no one in the driver's seat.

All such uses of Autopilot have been frowned upon by Tesla, which says drivers must read a safety notice every time they switch the system on; this tells them to only use it on freeways (motorways) and lightly touch the wheel at all times. An alert, ignored by some in the YouTube videos, reminds drivers to keep in contact with the wheel if the car senses they are not.