Congress in 2008 set in motion the safety upgrades in response to dozens of accidents in which children were backed over. At issue in particular were blind zones in large sport utility vehicles and pickups.
"There is no more tragic accident than for a parent or caregiver to back out of a garage or driveway and kill or injure an undetected child playing behind the vehicle," Transportation Secretary Ray LaHood said. He said the changes would "help drivers see into those blind zones directly behind vehicles to make sure it is safe to back up."
Nearly 300 people are killed and 18,000 injured each year because of backovers, according to data kept by the National Highway Traffic Safety Administration. Many happen in driveways and parking lots. Nearly half the deaths involve children under age 5, and the crashes also affect the elderly.
The agency estimated that the requirements could save 95 to 112 lives every year and prevent more than 7,000 injuries annually.
In about 70 percent of the cases, a family member is responsible for the death, said Janette Fennell, president of Kids and Cars, a Kansas-based safety group.
Automakers have added video cameras and object detection sensors to vehicles to help drivers when backing up or parking. Backup cameras are optional equipment on most vehicles; only about 20 percent of 2010 vehicles have the cameras onboard.
Automakers said they were reviewing the proposal but were supportive of efforts to keep children safe.
The proposal is expected to be completed next year after a public comment period. Under the plan, 10 percent of the vehicle fleet will need to meet the standards by the 2012 model year, followed by 40 percent in 2013 and all new vehicles by 2014.
The rules will apply to all passenger cars, SUVs, pickup trucks, minivans and other vehicles weighing up to 10,000 pounds. Under the plan, test objects would need to be visible in an area 20 feet behind the vehicle and about 5 feet to either side of the vehicle's center.
The government estimated the new requirements would cost about $1.9 billion to $2.7 billion.