Cars are about to get cameras very soon. US federal safety regulators have issued a final rule requiring all new automobiles with a gross vehicle weight rating of under 10,000 pounds (4,500 kg) including cars, buses, vans and trucks to be equipped with back-up cameras as a standard by May 2018.

The mandate is intended to prevent drivers from backing into pedestrians.

"Rear visibility requirements will save lives, and will save many families from the heartache suffered after these tragic incidents occur," said NHTSA Acting Administrator David Friedman. "We're already recommending this kind of life-saving technology through our NCAP program and encouraging consumers to consider it when buying cars today."

Cameras are to provide a 10 foot by 20 foot zone directly behind the car.

"Accordingly, based on an annual new vehicle fleet of 16.0 million vehicles and considering the number of vehicles we anticipate will already have rear visibility systems by 2018, we believe the costs attributable to equipping the remaining 27% of vehicles (that are not projected to have rear visibility systems in 2018) will range from $546 to $620 million annually," said NHTSA. "Those systems would also produce $265 to $396 million in monetized benefits."