They're supposed to limit damage in minor collisions, but many don't.
Recent or noteworthy IIHS research is compiled here.
See our comprehensive bibliography for more on this or any other topic.
Brake burnishing effect on AEB performance
Wilson, Myles; Aylor, David A.; Zuby, David S.; Nolan, Joseph M.
SAE Technical Paper 2015-01-1481
The Insurance Institute for Highway Safety (IIHS) evaluates autonomous emergency braking (AEB) systems as part of its front crash prevention (FCP) ratings. To prepare the test vehicles' brakes, each vehicle must have 200 miles on the odometer and be subjected to the abbreviated brake burnish procedure of Federal Motor Vehicle Safety Standard (FMVSS) 126. Other organizations conducting AEB testing follow the more extensive burnishing procedure described in FMVSS 135; Light Vehicle Brake Systems. This study compares the effects on AEB performance of the two burnishing procedures using seven 2014 model year vehicles. Six of the vehicles achieved maximum AEB speed reductions after 60 or fewer FMVSS 135 stops. After braking performance stabilized, the Mercedes ML350, BMW 328i, and Volvo S80 showed increased speed reductions compared with stops using brand new brake components. The Acura RLX and Cadillac CTS showed no change in speed reductions, and the speed reductions of the Dodge Durango and Lexus IS 250 worsened. After the FMVSS 135 burnishing was complete, AEB runs at 20 and 40 km/h were conducted to compare the results from the original IIHS FCP rating tests. For each of the vehicles, the IIHS FCP rating was not changed by different burnishing procedures. Results show that AEB speed reductions can improve or degrade as new brakes progress through the FMVSS 135 burnishing cycle. However, the differences in either direction are small and none of the tested vehicles had speed reduction differences that were great enough to change the IIHS FCP ratings.
Corner protection in low-speed crashes
Aylor, David A.; Nolan, Joseph M.; Avery, Matthew J.; Weeks, Alix M.
SAE Technical Paper Series 2007-01-1760
Safety: Rear Impact, Rollover, Side Impact, Crashworthiness, Air Bags and Bumper Systems (SP-2117)
Recent estimates of the annual cost to repair vehicle damage from motor vehicle crashes ranges from $17 billion (£9.1 billion) paid by U.K insurers to $45 billion paid by U.S. insurers. Many of these repairs were for damage sustained in low-speed front and rear impacts, with the majority costing less than $2, 500 to repair in both countries. In about a quarter of all claims the damage is limited to the vehicle corners and vehicle bumpers should prevent or limit much of the damage sustained in these minor crashes. However, many vehicles do not have bumper reinforcement beams that extend laterally much beyond the frame rails, leaving expensive vehicle components such as headlamps and fenders (wings) unprotected. Research by IIHS and Thatcham shows that 15 percent overlap front and rear crash tests at 5 km/h into a bumper-shaped barrier produce vehicle damage similar to that seen in real-world crashes and in vehicle-to-vehicle front-to-rear crash tests with low overlap. Tests also show that relatively minor modifications to bumper beams can greatly reduce the extent of this damage in low-speed collisions.
Limitations of current bumper designs and potential improvements
Aylor, David A.; Ramirez, Danny L.; Brumbelow, Matthew L.; Nolan, Joseph M.
SAE Technical Paper Series 2005-01-1337
Innovations in Modeling and Testing of Steel Structures for Automotive Applications, and Front and Rear Bumper Systems (SP-1954)
For every 100 insured passenger vehicles up to 3 years old, about 7 insurance claims are paid each year for collision damage to the insured vehicles, costing an average of $3,721 per claim. This excludes costs covered by collision insurance deductibles, which typically are $250 or $500. It costs about $265 per year per vehicle to pay these claims, excluding administrative costs. 1 It costs another $83 per year to pay for other property damage caused by the vehicles, typically to another vehicle in a two-vehicle collision (collision damage insurance covers damage to the insured vehicle; property damage liability insurance covers damage caused to other vehicles). 2 Thus the average recent model vehicle incurs crash damage costs of at least $348 per year. For 2003 the costs to repair these vehicles and the damage they caused would have totaled $16-18 billion, based on an estimated 47 million vehicles. The high cost of property damage in motor vehicle crashes also has been recognized by the federal government.
Important considerations in the development of a test to promote stable bumper engagement in low-speed crashes
Nolan, Joseph M.; Brumbelow, Matthew L.; Zuby, David S.; Avery, Matthew J.
SAE Technical Paper Series 2004-01-1319
The National Safety Council (2002) estimates that more than 20 million passenger vehicles in the United States are involved in crashes each year. The exact number of vehicles involved in low-speed property-damage-only crashes is not known because many of these crashes are not reported to police or insurers. Nevertheless, data from U.S. automobile insurers indicate that the over-whelming majority of crashes producing vehicle damage occur at relatively low speeds. Each year more than 8 percent of recent model passenger vehicles have crash damage leading to insurance claims, with an average repair cost per claim of more than $3,000. The median damage amount is about $2,000, and the most common amount is in the $600 to $700 range. Furthermore, about 80 percent of the damage claims have no associated injury claims ( Highway Loss Data Institute, 2003a , 2003b ). These data show that low-speed crash damage constitutes a large portion of the total costs to U.S. society for repairing crashed passenger vehicles. These costs are huge; in 2003 more than $4 billion was spent to repair 2002 model vehicles alone.
Types and extent of damage to passenger vehicles in low-speed front and rear crashes
McCartt, Anne T.; Hellinga, Laurie A.
Insurance Institute for Highway Safety
A survey of vehicles brought to five insurance drive-in claims centers in the Washington, D.C., metropolitan area was used to examine the types and amounts of vehicle damage sustained in relatively minor front and rear crashes. The sample of 509 vehicles included cars (67 percent), small and midsize sport utility vehicles (SUVs) (23 percent), and minivans (10 percent) of vehicle makes and models that had been evaluated in low-speed crash tests conducted by the Insurance Institute for Highway Safety. The mean estimated damage claim amount for cars in collisions with other cars ($820) was considerably lower than those for cars in collisions with SUVs ($1,189), minivans ($1,022), or pickups ($1,298). Of the cars involved in collisions with other vehicles, one-third sustained damage from bumper underride or override, and underride/override was associated with substantially higher mean estimated damage claim amounts. Underride/override was more common among cars sustaining front damage (39 percent) than among cars with rear damage (26 percent). Car-to-SUV crashes were particularly problematic; 67 percent of cars in these crashes sustained underride/override damage, and mean estimated claim amounts were 72 percent higher when this occurred. Underride/override occurred in about one-fifth of car-to-car crashes, usually after the bumpers initially engaged. Current low-speed vehicle crash tests do not capture the effects of underride or override, so these tests do not adequately measure the full extent of damage occurring in many real-world crashes, even for vehicles with equal bumper heights. Better low-speed crash tests to evaluate bumper performance and the implementation of meaningful federal bumper standards for SUVs, pickups, and vans, as well as cars, are needed to reduce the considerable damage costs resulting from underride and override.
Survey of vehicle owners regarding bumper performance
Cammisa, Michael X.
Insurance Institute for Highway Safety
Seven hundred owners of 1995-97 model year vehicles registered in Michigan and Texas were surveyed about their awareness of bumper performance data, how these data might affect future purchase decisions, and their opinions about current federal bumper regulations. A majority of respondents (61 percent) were aware of the availability of bumper performance data, and most who were aware said they had seen or heard this information on television (58 percent), followed by magazines (30 percent) and newspapers (27 percent). When purchasing their current vehicles, 17 percent considered bumper strength. When shopping for their next vehicles, most respondents said they would probably (37 percent) or definitely (20 percent) purchase vehicles with better bumpers over those with poorer bumpers. Seventy-seven percent of respondents expressed support for returning the bumper standard to 5 mph from the current 2.5 mph standard. When asked if the bumper standard should apply to vehicle types other than cars, 88 percent said it should. Overall, little difference was noted among respondents who recently had been in collisions with minor front or rear damage compared with those who had not.
Good bumpers...bad bumpers...big difference
Bottom Line Personal
November 15, 1996
When shopping for a new car, most people rarely consider the effectiveness of the cars bumper when making a decision. Yet bumper performance is one of the factors that insurance providers use to set rates.
Collision types and damage to cars brought to insurance drive-in claims centers
Wells, JoAnn K.; Gouse, S. William, III; Williams, Allan F.
Insurance Institute for Highway Safety
Little has been known about where and how low speed urban crashes occur and what kinds of vehicular damage they cause. A survey to collect such information was conducted at 16 drive-in claims centers maintained by four major insurers in four cities. Findings of particular interest include the substantial number of crashes that occur in parking lots and the extent to which bumper underride and override occur. More detailed study of parking lot collisions and ways to reduce them is needed, as are measures to reduce bumper underride and override and the ensuing damage.
Bumper performance levels and insurance loss experience
SAE Technical Paper Series 840224
Since the 1973 model year minimum levels of new car bumper performance have been specified by federal standards. Beginning with the 1974 model year, the safety bumper standard required that bumpers protect safety related equipment in 5 mph front-and rear-into-barrier tests. This standard was superceded in the 1979 model year by the no-damage standard which restricted dollar damage in the same tests. For 1983 and later models the barrier test speed requirements of the no-damage standard were reduced to 2.5 mph.
Analysis of the effectiveness of bumper standard FMVSS 215
Abramson, Paul; Stein, Howard S.; Cohen, Jay W.; Werner, John V.
Transportation Research Record 844
The primary objective of this paper is to evaluate the effectiveness of crash-protecting automobile bumpers as required by Federal Motor Vehicle Safety Standard 215 - Exterior Protection Passanger Cars. This study focused on three distinct versions of the standard: (a) the initial 1973 regulations that required compliance with a barriert test, (b) regulations after 1974 that required both a pendulum and an upgraded barrier test, and (c) regulations after 1978 that limited total vehicular damage as a result of the pendulum and barrier tests. Following the recommendations of several previous studies, insurance claims were used as the data base. A comprehensive data base provided by the State Farm Insurance Company was categorized by vehicle model years that represent four time periods - 1972, 1973, 1974-1978, and 1979 - and into vehicle-size classes, impact points, vehicle age, and repaired and replaced damaged bumper categories. By using reported claims and average cost of these claims as measures of effectiveness, it was shown that the model years with more protective bumper systems experienced significantly lower proportions of bumper-related claims relative to all property-damage claims. However, in general, these model years also had higher average repair costs. The reduced percentages of bumper-related claims were primarily attributable to decreased claims that involve bumpers being replaced rather than claims that involve bumper repair only.
Attitudes toward five-mile-per-hour bumper--a national survey among newer model car owners (conducted for the Insurance Institute for Highway Safety)
Opinion Research Corporation
Insurance Institute for Highway Safety
This report presents the results of a nationwide survey which Opinion Research Corporation has recently completed. The survey was done for The Insurance Institute of Highway Safety. Interviewing was conducted by telephone, from October 22 through October 27, 1981, and 1103 households were interviewed. The purpose of the survey was to measure attitudes of car owners toward bumpers that meet the five-mile-per-hour federal property damage bumper To qualify for an interview a respondent had to be at least 21 years old, a head or co-head of the household and own at least one 1979-82 passenger car -- the model years required to meet the five-mile-per-hour federal property damage bumper standard. The questionnaire used in the survey is included in the appendix of this report as are descriptions of the sampling methodology and the interviewing experience.