Following are excerpts from the April 2014 NHTSA report:
“We continue to believe that providing a driver with a view of the area behind the vehicle is currently the most effective way available to reduce backover crashes”
“our research to date shows that systems that afford drivers the ability to see the pedestrian behind the vehicle are the most successful at helping drivers avoid striking the pedestrian.”
“the data indicate the ultrasonic sensors are less able to detect children within their design detection zone as children generally do not reflect sensor signals”
“The data show that, it would take between 4.7 to 6.4 feet to stop the vehicle from 2.0 mph and 13.4 to 17.5 feet to stop the same vehicle from 5.0mph. Further, the available data suggest that most drivers conduct backing maneuvers at speeds greater than 2.0 mph. Thus, in situations where the pedestrian enters the sensor design detection zone after the vehicle has started backing, it is unlikely that the driver will avoid the crash (even assuming perfect sensor detection and quick driver response).”
“drivers with multiple-technology rear visibility systems avoided unexpected obstacles less successfully than drivers equipped with video-only systems.”
“In terms of longitudinal distance, advocacy groups such as the Advocates, KidsAndCars.org, and the Consumers Union recommended that any "gaps" between the rear coverage zone and the vehicle's rear bumper should be eliminated.”