Motor insurance companies could soon calculate premiums based on how often, where and when people drive their cars.
A "pay-as-you-drive" trial scheme, involving hundreds of drivers, is now being conducted by insurance company Norwich Union.
"Black box" devices are currently being fitted into 5,000 Norwich Union customer cars across the UK.
The cars involved in the pilot scheme belong to a wide range of motorists - from low mileage users to long distance drivers and those who live in rural areas to town dwellers.
The black box is smaller than a DVD case and can be installed either in the boot or passenger area of the car.
It records vehicle usage and sends the data to Norwich Union securely, using similar technology to that of mobile phones.
The pilot scheme will run for up to two years and once the findings are evaluated, Norwich Union will confirm whether pay-as-you-drive insurance will be rolled out to all customers.
Robert Ledger, programme director for the scheme, said: "We believe this initiative is a major breakthrough in the development of more tailored motor insurance premiums enabling us to treat all drivers as individuals.
"And we're confident our customers will fully appreciate the benefits too. The interest in the pilot scheme has been phenomenal.
"We could have filled the pilot twice over with the amount of requests we've had from interested motorists, not just within the UK but from drivers around the world," he added.