Q&As: Backover crashes

November 2009

1 What is a backover crash?

A backover crash occurs when a vehicle backs into a person such as a pedestrian or bicyclist, often when exiting a driveway or parking spot. These crashes typically are at low speeds and exclude crashes that involve multiple vehicles or vehicles that back into objects.

2 How widespread is the backover problem?

Government databases generally record only crashes on public roads; however, this is not where most backover crashes occur. Until recently no federal data system collected information on all backover crashes. Relevant information was gleaned from a review of crash data from the National Highway Traffic Safety Administration (NHTSA), hospital emergency department records, death certificates, and media sources. Because these sources may not capture all of the deaths and injuries, Congress directed NHTSA to develop a database of injuries and deaths in nontraffic events involving motor vehicles.1 In 2009, NHTSA launched the Not-in-Traffic Surveillance (NiTS) crash database of nontraffic events resulting in injuries and deaths, which can be used to calculate a national annual estimate. Based on 2007 NiTS data, NHTSA estimates that 221 deaths and 14,000 injuries occur annually in nontraffic backover crashes.2 In addition to these deaths and injuries, the Fatality Analysis Reporting System (FARS) reports an annual average of 71 backover fatalities on public roadways, yielding an estimated 292 total backover fatalities each year. The National Automotive Sampling System-General Estimates System (NASS-GES) estimates that 4,000 backover injuries occur on public roadways, yielding an estimated 18,000 annual backover injuries.3

3 Who is most likely to be injured or killed in a backover crash?

Young children and older people are most likely to be killed in a backover crash. Based on 2007 NiTS data, 103 of the estimated 292 annual deaths in backover crashes were children younger than 5, and 76 deaths were people 70 and older. Two-thousand of the 18,000 injuries that occur every year from backover crashes involve children younger than 5 and an additional 3,000 involve people 70 and older.3 A Canadian study of child pedestrian backover collisions occurring between 1993 and 2004 found that 52 percent of the children were younger than 5.4

4 Where do most backovers occur and who is the typical driver?

Most backover incidents don't happen on public roads. NHTSA estimates that about 41 percent of backover fatalities and nearly two-thirds of backover injuries occur in driveways and parking lots.3 A Canadian study on child pedestrian backover collisions found that one-third of the crashes occur in driveways.4 A review of child pedestrian deaths in Australia from 1996 to 1998 showed 86 percent of drivers in driveway crashes were members of the struck child's family or family friends.5

5 What types of vehicles are most often involved?

SUVs and pickup trucks are involved in more backovers than cars.3 These vehicles typically have larger blind zones and sit higher off the ground than cars, making it more difficult for drivers to see children and smaller objects near the rear of the vehicle. Consumer Reports has measured rear blind zones of vehicles since 2002. It reports that an average midsize SUV has a 23-foot blind zone behind the vehicle compared with 17 feet for an average sedan.6

6 Are there technologies available for detecting people behind a vehicle?

Technology used might one day be adapted to reduce the risk of backover crashes. Radar and ultrasonic-based parking aid systems are designed to detect objects near vehicles' rear bumpers and warn drivers of their proximity during parking maneuvers. However, current systems don't reliably detect people, especially small children. Rear parking camera systems also hold promise, but current systems are designed as parking aids and typically don't have a large enough field of view to see people quickly approaching the vehicle's path from the side. In addition, lenses that offer a wider field of view often have distorted images, and all camera systems have degraded views when the lens is covered with rain, snow, ice, or road dirt.

7 How do parking aid technologies work?

Ultrasonic and radar systems use sensors mounted in the rear bumper to determine the distance of objects or people from the vehicle. Audible signals (e.g., chimes) or visual signals (e.g., dash warning lights) indicate when an object has been detected. These signals may intensify (i.e., get louder or flash more rapidly) as the distance between the vehicle and the object or person narrows. Camera-based systems display the area behind the vehicle on a screen, which usually is mounted on the instrument panel as part of a navigation system. Newer systems combine cameras and radar or ultrasound to aid drivers when backing.

8 How effective are parking aid technologies in detecting people behind a vehicle?

In 2006, NHTSA tested 8 sensor-based and 3 visual (1 camera-based and 2 auxiliary mirror) systems. All of the sensor-based systems could detect a moving adult within the system-established detection zone when the vehicle was stationary. The size of the person had an effect on detection performance. Most systems' detection zones didn't extend near enough to the ground (within18 inches) to detect a crawling infant.7 All of the systems exhibited inconsistency in detecting people in the vehicle blind zone and also had zones where children weren't detected. Sensor-based systems typically can detect people only directly behind the vehicle. None of the systems tested had large enough detection zones to completely cover the blind zone around the vehicle.

The rearview camera systems displayed nearly the entire rear blind zone when the view was unobstructed (i.e. view not diminished by inclement weather, sun glare, or dirty lenses). The camera systems had clear images of the area behind the vehicle and allowed drivers to recognize a person. However, NHSTA noted that camera effectiveness depended on drivers reversing slowly enough (not more than 2 mph) to allow for adequate reaction time. The agency concluded that more research was needed to determine how drivers would use and react to camera systems before knowing if they would achieve full potential.

9 Are auxiliary rearview mirrors more useful than the newer technologies?

Two mirror systems NHTSA tested had substantial areas behind the vehicle where people couldn't be seen, and the images were subject to distortion due to the convexity of the mirror.7 Auxiliary mirrors are often placed on vertical rear windows or are mounted inside the vehicle near or on the rear pillars.

10 What else can be done to prevent backover crashes?

Technology to detect people behind vehicles isn't fully developed and perhaps will never be 100 percent effective so it is likely drivers will always need to be vigilant. The national "Spot the Tot" campaign, developed by Safe Kids Utah, encourages drivers to walk completely around a vehicle before getting in and to roll down windows to hear what is happening near the vehicle before backing. It also is suggested to teach children to move away from a vehicle when started and to have them stand in full view of the driver when backing.

11 Does the federal government require parking aid technologies in vehicles?

No. To reduce backover crashes Congress in February 2008 required NHTSA to amend the safety standards to expand the required field of view of motor vehicles, possibly through the addition of backing cameras. In March 2009, NHTSA released an advanced notice of proposed rulemaking seeking comments on the proposed modification of Federal Motor Vehicle Safety Standard 111 (rearview mirrors) to improve the ability of a driver to see areas behind a motor vehicle to reduce backover incidents.8 The Institute urged the agency to establish a no blind zone requirement, or at least a minimum blind zone area, including a minimum distance from the rear of a vehicle that must be visible to the driver, either directly or with the aid of mirrors or other vision aids.9 Congress also directed NHTSA to work with manufacturers to develop systems on automatic transmission vehicles that require the brakes to be engaged before the gear can be shifted out of park for all vehicles sold after Sept. 1, 2010.1

References

¹US House of Representatives. H.R. 1216: Cameron Gulbransen Kids Transportation Safety Act of 2007. Washington, DC: US Congress.

²National Highway Traffic Safety Administration. 2009. Not-in-Traffic Surveillance 2007-highlights. Report no. DOT HS-811-085. Washington, DC: US Department of Transportation..

³National Highway Traffic Safety Administration. 2008. Fatalities and injuries in motor vehicle backing crashes: Report to Congress. Washington, DC: US Department of Transportation.

⁴Nhan, C.; Rothman, L.; Slater, M.; Howard, A. 2009. Back-over collisions in child pedestrians from the Canadian hospitals injury reporting and prevention program. Traffic Injury Prevention 10:350-53.

⁵Nee, T.; Wylie, J.; Attewell, R.; Glase, K.; and Wallace. A. 2002. Driveway deaths: fatalities of young children in Australia as a result of low-speed motor vehicle impacts. Australian Transport Safety Bureau. Road Safety Report CR208.

⁶Consumer Reports. 2008. Vehicle blind spots. http://www.consumerreports.org/cro/cars/car-safety/car-safety-reviews/mind-that-blind-spot-1005/overview/index.htm (accessed September 23, 2009).

⁷National Highway Traffic Safety Administration. 2006. Vehicle backover avoidance technology study: Report to Congress, Washington, DC: National Highway Traffic Safety Administration.

⁸National Highway Traffic Safety Administration. 2009. Federal Motor Vehicle Safety Standard: Rearview mirrors; proposed rule. Federal Register Vol. 74, No. 41: 9478-9520.

⁹Insurance Institute for Highway Safety. 2009. Comment to the National Highway Traffic Safety Administration concerning proposed amendments to rearview mirrors safety standard, May 1; Docket no. NHTSA-2009-0041. Arlington, VA.