High technology comes with price and privacy concerns

Drivers in California can now opt to have digital number plates fitted to their vehicles, but take up is expected to be low.

According to the Sacramento Bee, the new digital plates will cost a pretty penny: the initial purchase price is US$699 ($925) excluding fitting, and there's also a US$7 ($9.30) per month fee.

The plates being trialled are made by Reviver Auto, and feature an e-ink display, similar to the one used on the Amazon Kindle. These displays require much less power to operate than LCD or OLED screens, and produce an image that's easily visible in bright sunlight.

Reviver Auto's digital number plates include their own battery, processing unit, GPS receiver, and wireless connectivity. The latter system allows drivers to renew their registration without having to step into a DMV (Department of Motor Vehicles) office, or affix registration stickers to their plates.

If the car is reported as being stolen, the plate automatically displays "STOLEN", and allows police to track the vehicle, or discover its last known position if the plates are removed.

When the vehicle is parked, plate info can be shrunk into the top right-hand corner, and the majority of the display used for messages, traffic alerts, or advertising.

Unlike regular licence plates, the new digital versions are only available through car dealerships, and cannot be purchased through the state's DMV.

During the trial period, digital plates can only be used in up to 0.5 per cent of all cars registered in California, or around 175,000 vehicles.

The DMV told the newspaper there are only 116 units being used right now. Reviver Auto says it expects this number to jump into the thousands.

The city of Sacramento has been given 24 plates to test out, although they will need to convince labour unions the plates won't be used to track employees.

Dubai announced a similar trial scheme for digital licence plates earlier this year.