2015 Tesla Model S 7.0 first drive

The latest software update for the Tesla Model S features the company’s Autopilot technology. While it’s some way from being the autonomous car promised by the futurists, it takes great strides towards making driving in heavy traffic much less of a chore.

A £2100 option, the system introduces ‘traffic aware cruise control’ (Tesla’s version of the familiar radar cruise), automatic parallel parking, side collision avoidance and automatic lane changing.

Model S cars that were built in the past 12 months or so are already fitted with the sensors needed for the autopilot feature. These include ultrasonic sensors (which give the car’s brain a 360-degree view of its immediate surroundings) and forward-facing radar sensors. The car also has a forward-facing camera. 

Autopilot uses these sensors in combination with GPS-driven satellite navigation and ‘high precision digital maps’ to give the car a pretty comprehensive idea of where it is, where other cars are, where the road is heading and how close it might be to the central reservation on the motorway.

The 7.0 update also features redesigned screen graphics in the main instrument binnacle, giving the option of a display that’s dominated by a rendering of the car sitting in a single lane. When the car’s forward-facing camera detects white lines (constant or broken) the graphic shows these as defined edges on the virtual road. This is a good indication that the Model S’s autopilot system is confident enough to engage.

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.