A black box doesn't stop you from driving at certain times, etc. But it is linked to your insurance and your premiums change according to how you drive - the data is uploaded and analysed.
According to Money Supermarket website:
So what are the drawbacks?
Although black box insurance seems like a much fairer system, it's not without its drawbacks. One is that you could have the cost of the 'black box' and its installation added to the cost of your cover. However, it is unlikely that this will outweigh the potential savings.
Another drawback is that, if you cover a lot of miles, say during a lengthy commute to work and back, you may not see any savings at all - and may even end up paying more than if you had taken out a traditional policy.
In addition, if it turns out that you are not as safe and considerate a driver as you first thought, you may also end up paying more for your cover. However, the way the system works means that you would at least have a chance to put this right.
And while it may seem a little unsettling to have your every move tracked via satellite, this can have its advantages. For instance, it can pinpoint blame if you are involved in a collision or can even trace your vehicle if it is stolen.