Reporter: An anxious day for any young driver, but for parents the worries don’t end there.

Driver: I usually take this roundabout a lot faster than (laughs) this!

Reporter: Teenagers drive faster and take more risks. Within a year of passing their test, one in five has had a crash. Now, Ford says it’s given parents peace of mind when they hand over the car. This programmable key can limit speed, restrict the volume of the stereo and even mute it altogether if occupants don’t buckle up.

Spokesman: You actually have two keys – one is the parent key, one is the teen key. Using the parent key, you actually go into the vehicle, er, you get some messaging on the instrument cluster where you can set the speed, you can set the audio volume, er, the seat belt usage is automatically programmed so that when that younger driver then comes into the vehicle, the limits are already set.

Reporter: Andrea Smith believes her son Kyle would still be alive if he’d been wearing a seat belt. He was thrown through a window when the driver of the car lost control. She welcomes any attempt to improve safety.

Andrea: Once you, you give somebody a licence, you are giving them a licence to kill, and I think as soon as those, you know, youngsters get hold of a licence, I don’t think they really, really realise what they’ve got their hands on.

Reporter: But the “My Key” system only allows parents to limit the top speed to 80 miles an hour. Below that, their children will just get a warning chime. That’s pointless, says this motoring expert at the technology website, CNET. 

Expert: You can still break the law, even though this system is “limiting” you to a certain speed. It also doesn’t take into account things like your rate of acceleration. You can still engage in a drag race with your friends at the lights and get up to speeds of 80 miles an hour in a 30 zone, for example, if you’re stupid enough.

Reporter: On Britain’s congested roads, cars are increasingly being fitted with radars, lasers and cameras to keep motorists in their lane and a safe distance apart. It’s not just young drivers who are giving up control to a computer. Thomas Moore, Sky News.