Q&A: Backover crashes

August 2012

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. Crashes that involve multiple vehicles or vehicles that back into objects aren't considered backover crashes.

2 How widespread is the backover problem?

Government databases generally record only crashes on public roads, but most backover crashes occur in driveways and parking lots. Until recently no federal data system collected information on all backover crashes. An overall picture could be 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. US House of Representatives. H.R. 1216: Cameron Gulbransen Kids Transportation Safety Act of 2007. Washington, DC: US Congress.

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. National Highway Traffic Safety Administration. 2009. Not-in-Traffic Surveillance 2007:highlights. Report no. DOT HS-811-085. Washington, DC: US Department of Transportation. In addition to these deaths and injuries, an average of 71 backover fatalities are reported each year on public roadways, yielding an estimated 292 total backover fatalities each year. An estimated 4,000 backover injuries occur on public roadways, yielding an estimated 18,000 annual backover injuries. National Highway Traffic Safety Administration. 2008. Fatalities and injuries in motor vehicle backing crashes: Report to Congress. Washington, DC: U.S. Department of Transportation.

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. About 2,000 of the 18,000 injuries that occur every year from backover crashes involve children younger than 5, and 3,000 involve people 70 and older. National Highway Traffic Safety Administration. 2008. Fatalities and injuries in motor vehicle backing crashes: Report to Congress. Washington, DC: U.S. Department of Transportation. A Canadian study of child pedestrian backover collisions occurring between 1993 and 2004 found that 52 percent of the children were younger than 5. Nhan, C.; Rothman, L.; Slater, M.; Howard, A. 2009. Back-over collisions in child pedestrians from the Canadian hospitals injury reporting and prevention program. Traffic and Injury Prevention 10:350-53.

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

Most backover incidents don't happen on public roads. NHTSA estimates that 39 percent of backover fatalities occur in residential spaces such as driveways and the parking lots of apartment and townhouse complexes. Nonresidential parking lots account for only 17 percent of backover fatalities, but 52 percent of backover injuries. National Highway Traffic Safety Administration. 2008. Fatalities and injuries in motor vehicle backing crashes: Report to Congress. Washington, DC: U.S. Department of Transportation.

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. Nee, 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. Road Safety Report no. CR208. Canberra, ACT: Australian Transport Safety Bureau. Another Australian study in Queensland found that parents were driving in 11 of the 15 low-speed run-over fatalities of children that occurred in the state in 2004-08. The study included cases in which the vehicles were moving forward, as well as reversing. Griffin, B.; Watt, K.; Wallis, B.; Shields, L.; and Kimble, R. 2011. Paediatric low speed vehicle run-over fatalities in Queensland.Injury Prevention 17:10-13.

5 What types of vehicles are most often involved?

SUVs and pickup trucks are involved in more backovers than cars. National Highway Traffic Safety Administration. 2008. Fatalities and injuries in motor vehicle backing crashes: Report to Congress. Washington, DC: U.S. Department of Transportation. These vehicles typically have bigger blind zones, in large part because they sit higher off the ground, making it more difficult for drivers to see children and smaller objects near the rear of the vehicle.  Consumer Reports measures rear blind zones of vehicles and has found that, for a 5-foot-8-inch-tall driver , an average midsize SUV has an 18-foot blind zone behind the vehicle, compared with 13 feet for an average midsize sedan. Blind zones for shorter drivers are much bigger. Consumer Reports. 2012. Best and worst rear blind zones. Available: http://www.consumerreports.org/cro/2012/03/the-danger-of-blind-zones/index.htm. Accessed: August 4, 2012.

An analysis of driveway backovers involving children in Utah from 1998 to 2003 found that children were 53 percent more likely to be injured by a pickup truck than a car and 2.4 times more likely to be injured by a minivan, relative to the number of registered vehicles of each type. There wasn't a significant difference between injury rates for SUVs and cars. However, the results may have been skewed by the fact that minivans are more likely to be owned by families with children. Pinkney, K.; Smith, A.; Mann, N.; Mower, G.; Davis, A.; and Dean, J. 2006. Risk of pediatric back-over injuries in residential driveways by vehicle type. Pediatric Emergency Care 6:402-407.

6 What technologies are available for detecting people behind a vehicle?

Rearview video cameras hold the most promise for reducing backover crashes, and a federal law is expected to result in their installation in all vehicles. In the past, such cameras were marketed primarily as parking aids, not safety devices. The systems display the area behind the vehicle on a screen, which usually is mounted on the instrument panel as part of a navigation system.

Other types of parking aids that rely on radar or ultrasonic sensors have also been studied for their ability to prevent backovers but are considered less reliable for this purpose. These systems produce audible or visual signals to warn a driver if an object is detected behind a reversing vehicle. The signals may intensify as the distance between the vehicle and the object or person narrows. A NHTSA evaluation conducted in 2006 found that eight sensor-based systems could detect a moving adult when the vehicle was stationary, but all of them performed inconsistently and had areas where children weren't detected. National Highway Traffic Safety Administration. 2006. Vehicle backover avoidance technology study: Report to Congress. Washington, DC: National Highway Traffic Safety Administration. As a result, drivers may not trust these systems or use them at all. Mazzae, E.N. and Barickman, F. 2008. On-road study of drivers’ use of rearview video systems. Report no. DOT HS-811-024. Wasington, DC: US Department of Transporation. Llaneras, R.E.; Green, C.A.; Kiefer, R.J.; Chundrilk Jr., W.J.; Altan, O.D.; and Singer, J.P. 2005. Design and evaluation of a prototype near obstacle detection and driver warning system. Human Factors 47(1): 199-215.

Some newer systems combine cameras with radar or ultrasound sensors.

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. Although NHTSA has yet to finalize the regulation, the agency says cameras are the only currently available technology that could meet the requirement. National Highway Traffic Safety Administration. 2010. Federal Motor Vehicle Safety Standard, Rearview mirrors; Federal Motor Vehicle Safety Standard, Low-Speed Vehicles Phase-In Reporting Requirements; proposed rule. Federal Register Vol. 75, No. 234: 76186-76250.

7 Will requiring rearview cameras eliminate backover crashes?

No. NHTSA estimates that 95 lives will be saved by the requirement. The actual effectiveness will depend on how drivers use the systems A review of research conducted by General Motors and the Virginia Tech Transportation Institute indicated that factors such as experience with rearview cameras, expectations regarding the likelihood of an obstacle during backing, and the timing of glances to the camera images influence the use and subsequent benefits of these systems. Llaneras, R.; Neurauter, M.; and reen, C. 2011. Factors moderating the effectiveness of rear vision systems: what performance-shaping factors contribute to unexpected in-path obstacles when backing? SAE 2011 World Congress & Exhibition Paper no. 2011-01-0549. Warrendale, PA: Society of Automotive Engineers.

Pairing rearview cameras with sensor systems could make the cameras even more effective. A study in which 46 drivers completed 16 parking trials found that only 20 percent of drivers looked at the camera image before backing. Of those who didn't, 46 percent looked at it after the sensor issued an audible warning. Hurwitz, D.; Pradhan, A.; Fisher, D.; Knodler, M.; Muttart, J.; Menon, R.; and Meissner, U. 2010. Backing collisions: a study of drivers' eye and backing behavior using combined rear-view camera and sensor systems. Injury Prevention 16:79-84.

Another issue is that large blind zones will remain in many vehicles even after the addition of cameras. The size of those zones could be reduced in many cases simply through better vehicle design that increases the directly viewable area. The Institute has urged NHTSA to adopt a requirement that would eliminate unnecessary blind zones after finalizing the camera requirement. Insurance Institute for Highway Safety. 2011. Comment to the National Highway Traffic Safety Administration concerning proposed amendments to rearview mirrors safety standard. Docket no. NHTSA-2010-0162. January 31, 2011. Arlington, VA.

8 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. National Highway Traffic Safety Administration. 2006. Vehicle backover avoidance technology study: Report to Congress. Washington, DC: National Highway Traffic Safety Administration. Auxiliary mirrors are often placed on vertical rear windows or are mounted inside the vehicle near or on the rear pillars.

9 What else can be done to prevent backover crashes?

Technology may never be 100 percent effective so 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 suggests teaching children to move away from a vehicle when started and to have them stand in full view of the driver when backing.

Separating children's play areas from driveways also may help. A study in New Zealand in the 1990s found that children in homes without a fence separating the driveway from the play area were 3½ times more likely to be killed or injured in a driveway crash. Roberts, I.; Norton, R.; and Jackson, R. 1995. Driveway-related child pedestrian injuries: a case-control study. Pediatrics 95:405-408.