First test - Land Rover Discovery’s new trailer parking for dummies system

Now the Terrain Response dial is used to guide the trailer. You still need to control the speed using the pedals (the slower you reverse, the more time you give yourself) but the Discovery steers of its own accord, calculating the angle of reverse steering input that’s required.

To begin with it feels counterintuitive to control the vehicle using a rotary dial, particularly when the steering wheel is whipping left and right of its own accord. I found myself paying scant attention to my physical surroundings as I focused on the reversing camera - probably not a sensible state of affairs when you’re reversing an awkward long load into a tight space.

Nevertheless, as I got comfortable with the system it made reversing much simpler, particularly when I learned to appreciate how the slightest of adjustments on the Terrain Response dial make quite a significant difference to the trailer’s angle of attack.

One other factor is that you can't see the top of the trailer in the reversing camera, so it's worth assessing any overhanging obstructions beforehand if you're parking in unfamiliar territory.

If you end up in a situation where the trailer is neatly lined up but the towing Discovery is crooked (as I did) you simply leave the rotary dial on a dead-ahead trajectory and the system will turn the car around the pivot point of the trailer to straighten out the vehicle. On the other hand, if the system senses that you’re asking for an amount of steering that’s going to end up with car and trailer jacknifing, it sounds an alert.

Before it can be used the system requires a simple calibration process that includes asking drivers for some basic dimensions and other details of their loads, such as how many axles it has. Once the information is inputted it is stored in the system, and owners who haul more than one load can toggle between them in the menu.

The second element of calibration is affixing a tracking target sticker to the front of the trailer where it can be seen by the reversing camera. This target sticker is the key to the technology that makes the system work, enabling the car’s computer processor to determine the angle of the trailer.

Land Rover isn’t the only company rolling out this kind of technology. The Audi Q7 offers a variation on the theme, for example. It's a useful system for those who regularly find themselves in tricky towing situations and a neat example of how autonomous driving can support the driver rather than completely rob them of control.