Bumper Questions and Answers (original) (raw)

Bumper Q&A's

1) What is a bumper?

A bumper is a shield made of steel, aluminum, rubber, or plastic that is mounted on the front and rear of a passenger car. When a low speed collision occurs, the bumper system absorbs the shock to prevent or reduce damage to the car. Some bumpers use energy absorbers or brackets and others are made with a foam cushioning material.

2) What is the purpose of bumpers?

The car bumper is designed to prevent or reduce physical damage to the front and rear ends of passenger motor vehicles in low-speed collisions. Automobile bumpers are not typically designed to be structural components that would significantly contribute to vehicle crashworthiness or occupant protection during front or rear collisions. It is not a safety feature intended to prevent or mitigate injury severity to occupants in the passenger cars. Bumpers are designed to protect the hood, trunk, grille, fuel, exhaust and cooling system as well as safety related equipment such as parking lights, headlamps and taillights in low speed collisions.

3) What are the Federal regulations for bumpers?

49 CFR Part 581, "The bumper standard," prescribes performance requirements for passenger cars in low-speed front and rear collisions. It applies to front and rear bumpers on passenger cars to prevent the damage to the car body and safety related equipment at barrier impact speeds of 2� mph across the full width and 1� mph on the corners.

This is equivalent to a 5 mph crash into a parked vehicle of the same weight. The standard requires protection in the region 16 to 20 inches above the road surface, and the manufacturer can provide the protection by any means it wants. For example, some vehicles do not have a solid bumper across the vehicle, but meet the standard by strategically placed bumper guards and corner guards.

4) Are all vehicle classes required to meet the Federal bumper standard?

No. The Federal bumper standard does not apply to vehicles other than passenger cars (i.e., sport utility vehicles (SUVs), minivans, or pickups trucks). The agency has chosen not to regulate bumper performance or elevation for these vehicle classes because of the potential compromise to the vehicle utility in operating on loading ramps and off road situations.

5) When did the bumper standard first come into effect and how has it changed over the years?

On April 9, 1971, the agency issued its first passenger car bumper standard -- Federal Motor Vehicle Safety Standard (FMVSS) 215, "Exterior Protection," which became effective on September 1, 1972. This standard called for passenger cars, beginning with model year (MY) 1973, to withstand 5 mph front and 2 � mph rear impacts against a perpendicular barrier without damage to certain safety-related components such as headlamps and fuel systems.

In October 1972, Congress enacted the Motor Vehicle Information and Cost Saving Act (MVICS Act) which mandated that the agency issue a bumper standard that yields the maximum feasible reduction of costs to the public, taking into account the cost and benefits of implementation, the standard's effect on insurance costs and legal fees, savings in consumer time and inconvenience, and health and safety considerations.

The new requirements under the MVICS Act were then consolidated with existing requirements in FMVSS 215 and promulgated in March 1976 as a new bumper standard, which was added to NHTSA's regulations at 49 CFR Part 581. The new standard which applied to passenger cars beginning with MY 1979, was referred to as the Phase I Standard. At the same time, a "no damage" requirement (Phase II) was placed on bumper systems for model year 1980 and subsequent years. (See question 6 for more information on Phase I and II requirements.)

The most recent revisions to the bumper standard took place in May 14, 1982, effective for MY 1983 and subsequent model year passenger cars. This amendment reduced test impact speeds from 5 mph to 2.5 mph for longitudinal front and rear barrier and pendulum impacts and from 3 mph to 1.5 mph for corner pendulum impacts. In addition, Phase I damage resistance criteria were substituted for Phase II criteria and a bumper height requirements of 16 to 20 inches was established for passenger cars.

6) What do Phase I and Phase II mean? How do they differ and how much damage does the standard allow?

Phase I and II refer to a two-phased rulemaking action on bumper requirements. Phase I of the standard became effective on September 1, 1978 for passenger cars beginning with MY 1979. It incorporated the FMVSS 215 safety criteria, and added new performance criteria which prohibited damage to all exterior vehicle surfaces. For MY 1979, the standard required that there be no damage to safety-related parts and exterior surfaces not involving the bumper system(e.g., sheet metal; lamps; and fuel, exhaust and cooling systems) with damage to the facebar and its fasteners at impact test speed of 5 mph front and rear impacts with barrier and pendulum; 3 mph corner impact with pendulum.

More stringent damage resistance criteria known as Phase II became effective one year later, on September 1 1979, for MYs 1980 to 1982, and consisted of 5 mph longitudinal front and rear impacts with barrier and pendulum; 3 mph corner impact pendulum, all with no damage to the bumper itself beyond a 3/8 inch dent and 3/4 inch set or displacement from original position.

7) Has NHTSA conducted evaluations of the bumper standard? If so, what were the results?

Yes. NHTSA conducted an evaluation of the bumper standard in 1981. The evaluation determined the net benefits (the change in costs) to the consumer attributable to each successive standard (applicable through MY 1980) in relation to unregulated bumper systems in MY 1972 and prior years. The evaluation findings were that bumper systems complying with the standard requirements for model years 1979 and 1980 (most, if not all, bumpers were built to the 1980 "no damage" standard in 1979) tended to show net consumer losses - based on a 10-year car life - when compared to unregulated bumper systems. The costs of the 1979/1980 systems were between 150and150 and 150and200 higher than the unregulated bumpers (1972 and earlier model years).

In 1987, the agency conducted another evaluation of the bumper standard. The evaluation concluded that: (1) the costs to consumers did not change as a result of the modification of the bumper standard from 5 to 2.5 mph; (2) the net effect, over a car's 10 year life, is a small increase in repair costs, which is offset by a reduction in the cost of the bumpers; and (3) the change in the bumper standard did not compromise the protection of safety-related parts.

8) Why did NHTSA lower the bumper standard requirements from 5 mph to 2� mph?

The agency concluded that reducing the impact speed from 5 mph to 2� front and rear impact speed best satisfied the statutory criteria that the bumper standard "seek to obtain maximum feasible reduction in costs to the public and to the consumer." The agency also concluded that reducing the impact speed to 2� mph and eliminating the Phase II damage criteria would not have an adverse effect on safety as measured by the number of crashes, deaths or injuries that occur annually.

The agency set the protection standard at 2� mph after studying the comparable repair costs of a 5 mph bumper that has higher energy absorption capacity along with additional cost and weight.

After public hearings involving all parties, including consumers and manufacturers, NHTSA concluded that the public is assured of the largest net benefits under a standard that requires 2� mph protection for both the front and rear bumpers.

9) How does the U.S. the bumper standard compare to the Canadian and European standards?

Under the Canadian bumper standard, the vehicle is impacted into a fixed-collision barrier that is perpendicular to its line of travel while the vehicle is traveling longitudinally forward at 8 km/h (5 mph) and longitudinally backward at 8 km/h (5 mph), with its engine operating at idle speed. Every vehicle is impacted twice on the front and rear surfaces and once on each front and rear corner with the impact line at any height between 500mm (20 inches) and 400mm (16 inches). While the impact speed in the Canadian standard is higher than that in the U.S. standard, the Canadian standard has less stringent protective criteria. Specifically, the protective criteria for the Canadian standard requires that the vehicle does not touch the test device, except on the impact ridge with a force that exceeds 2000 lbs. on the combined surface of the test device.

The United Nations Economic Commission for Europe (ECE) regulation No. 42 requires that a car's safety systems continue to operate normally after the car has been impacted by a pendulum or moving barrier on the front or rear longitudinally at 4 kilometers per hour (about 2.5 mph) and on the front and rear corner at 2.5 kilometers per hour (about 1.5 mph) at 455 mm (about 18 inches) above the ground under loaded and unloaded conditions.

10) How do I know if my vehicle meets or exceeds the Federal bumper standard?

Manufacturers self-certify their products in order to meet the bumper standard, as well as all applicable Federal motor vehicle safety standards. Since this is a minimum performance standard, the manufacturer may be providing a greater level of protection. The agency does not require manufacturers to report the actual performance capabilities of their bumper systems.

Although many manufacturers voluntarily include bumper performance information on the window stickers of new passenger cars sold in United States, only California and Hawaii have bumper performance disclosure laws that require manufacturers to be specific about its performance capabilities.

11) Is there a way to determine how fast a car was going during a rear end crash based on the damaged bumper(s)?

No. We do not collect any data that would be useful in determining the impact speed. Many parameters such as vehicle masses, the pre-impact velocity of both vehicles, impact angles, crush resistance, metallurgical fatigue, etc., affect how the bumpers behave during an impact. Each crash must be analyzed with respect to all of the parameters before an estimate can be made.

12) Does NHTSA conduct any low-speed crash tests of bumpers and rate their relative performance?

NHTSA does not conduct low-speed impact crash tests of bumpers to rate their comparative performance due to the costs associated with this type of program. However, the Insurance Institute for Highway Safety (IIHS) conducts yearly tests on a number of models for bumper ratings (in terms of strength and repair cost). Information can be obtained through their web site at: http://www.hwysafety.org or at (703) 247-1500.

The agency's New Car Assessment Program (NCAP) conducts yearly crash tests to provide consumers with information about levels of protection when the vehicles are tested in a frontal barrier crash and when struck in the side by a moving barrier device. The 'star' ratings that reflect performance on these tests would better assist a consumer seeking to select a safe vehicle. These ratings can be obtained through our web site at: http://www.nhtsa.dot.gov

13) Why are bumpers on light trucks or SUVs higher than the those on passenger cars?

Bumpers are typically higher on light trucks, pick-ups or SUVs than on passenger cars to provide better clearance for approach and departure of steep grades or when driving over large rocks and other objects during off road operations.

14) Does the Federal government specify uniform bumper heights for vehicles to prevent damage in low-speed collisions?

No, NHTSA regulates the height and impact capabilities of bumpers only of passenger cars, but not for light trucks, minivans or SUVs. However, some states and localities have requirements that limit bumper height for other vehicle types. We suggest individuals contact their local or state agency responsible for motor vehicle regulations.

15) What is NHTSA doing to address bumper mismatch issue between passenger cars and SUVs?

The agency is aware that there is a mismatch between the bumpers of passenger cars and those of some light trucks and vans (LTVs). However, bumper elevation is not solely responsible for mismatched contact in vehicle collisions. The effect of braking and interaction of suspension dynamics and vehicle weight can also be attributed to the mismatch. This issue is being addressed as a part of the agency's consideration of the broader issue of vehicle compatibility. Compatibility involves differences in vehicle characteristics between passenger cars and LTVs such as weight, height off the ground, geometry and stiffness. To address this issue, the agency is developing advanced simulation models of vehicles that could be used as tools to understand crash behavior and interactions between incompatible vehicles and to assess safety implications of these vehicles fleet wide. This research could lead to the development of suitable countermeasures for occupant protection in crashes of incompatible vehicles by transferring loads through structural members which interact better in crashes and through energy management while maintaining occupant compartment integrity. Based on the results of the agency's research, rulemaking actions related to the bumper and/or other Federal standards may be undertaken to address the vehicle compatibility issue.