In heavy motorway traffic, very impressive. The automatic parking and radar cruise control features are already well established in many new cars, but the automatic lane changing is a step-change for driving assistance.
The European version of the 7.0 update differs from the US software in that the driver has to have their hands in contact with the steering wheel - albeit very lightly - for the car to execute an automatic lane change.
We tried the autopilot system on the Eastern end of the M4 motorway, looping from Heathrow into the centre of the capital and back. There’s no doubt that the autopilot is at its best in relatively heavy traffic.
When the car’s all-round sensors have something to lock onto, as well as white lines to help it centre itself in a lane, the Model S runs very confidently in the traffic, automatically adjusting its speed and slowing neatly so it can roll along in the flow.
The radar cruise control is activated by tipping a lever on the left side of the steering column, but the set speed can only be adjusted in 5mph increments, which is a bit limiting for the UK’s cramped roads. Pulling the same lever twice towards the driver activates the automatic steering and lane change features.
The self-steering works very well in heavy traffic. It’s remarkable just how much strain is lifted from the driver when the car not only keeps itself centred in a lane, but also a discrete (three-stage adjustable) distance from the car in front.
On first experience, auto lane changing is not quite as effortless as simply following a lane, mostly because years of driving instinct is against it. It is activated by flicking the indicator stalk, while covering the wheel rim with your hands. There’s no need to grip the wheel, but it takes quite a lot of counter-intuitive effort to allow the Tesla to execute the lane change unaided.
There’s no doubt it works, though. The car moves crisply into the next lane and centres itself in a second or so. After a few hours at the wheel of an autopilot-equipped Model S, I’m certain the driver would be confidently letting the car change lanes without much thought.
Running off the end of the M4, on to an urban three-lane dual carriageway, the self steering feature still worked surprising well, despite the confusion that can be caused by yellow boxes, cross-hatch lane markings and faded lines.
However, the system is intelligent, so the more miles an autopilot-equipped Model S' covers, the more efficient subsequent software updates will be. This is because the information that autopilot-equipped cars ’learn’ about differing road conditions around the world is uploaded to the Tesla cloud.