Frontal offset crash test program

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About half of all passenger vehicle occupants killed on U.S. roads die in frontal crashes. Major strides have been made in frontal crash protection, thanks in large part to the crash test program the government began in the late 1970s and the offset tests the Institute began in 1995.

Two different tests

The Institute's frontal offset crash test (bottom left) is different from the government's frontal crash test (top left). In the federal New Car Assessment Program, passenger vehicles are crashed at 35 mph into a rigid barrier that covers the full width of the vehicle.

The federal program has been extremely successful. Automakers responded by improving their vehicles to earn good ratings in the tests, giving them a higher level of frontal crashworthiness than is required by law. By the 1990s, most vehicles were performing well in the full-width frontal test.

But this improvement didn't mean there were no longer any differences in frontal crashworthiness among vehicles. What it meant was that new kinds of tests were needed to highlight those differences. That's where the frontal offset test came in.

In an offset crash only one side of a vehicle's front end, not the full width, hits the barrier. As a result, a smaller part of the structure has to manage the crash energy, and intrusion into the occupant compartment is more likely. An offset test is more demanding of a vehicle's structure than a full-width test, while a full-width test is more demanding of a vehicle's safety belts and airbags. Together the two tests provide a more complete picture of frontal crashworthiness than either test by itself.

The Institute's frontal offset test

In the Institute's test, a vehicle travels at 40 mph toward a barrier with a deformable face made of aluminum honeycomb. A Hybrid III dummy representing an average-size (50th percentile) man is positioned in the driver seat. Forty percent of the total width of the vehicle strikes the barrier on the driver side.

The forces in the test are similar to those that would result from a frontal offset crash between two vehicles of the same weight, each going just under 40 mph.

Ratings criteria

Engineers consider three factors to determine a vehicle's frontal rating: structural performance, injury measures, and dummy movement.

Structure/safety cage: To assess a vehicle's structural performance, engineers measure the amount of intrusion into the occupant compartment after the crash. Measurements are taken at nine places around the driver's seat (right). The amount and pattern of intrusion shows how well the front-end crush zone managed the crash energy and how well the safety cage held up.

Injury measures: Injury measures from the dummy in the driver's seat are used to determine the likelihood that a driver would sustain various types of injuries in a similar real-world crash. The numbers recorded from the head, neck, chest, legs, and feet of the dummy indicate the level of stress or strain on that part of the body — in other words, the risk of injury.

Restraints/dummy movement: Even if injury measures are low, it's important to consider the dummy's movement during the crash, since not all drivers are the same size as the dummy or seated exactly the same way. A close call for the dummy could be an actual injury for a person.

Before each crash test, technicians put grease paint on the dummy's head, knees and shins. After the test, the paint shows what parts of the vehicle came into contact with those parts of the dummy. The paint, combined with high-speed film footage of the crash, allows engineers to evaluate the dummy's movement.

Although this assessment is important, it doesn't contribute as much as structural performance or injury measures to each vehicle's overall evaluation.

Understanding the ratings

How much better do vehicles that earn good ratings perform in real-world frontal crashes?

An analysis of 14 years worth of crash data involving Institute-rated vehicles shows that a driver of a vehicle rated good is 46 percent less likely to die in a frontal crash, compared with a driver of a vehicle rated poor. A driver of a vehicle rated acceptable or marginal is 33 percent less likely to die than a driver of a poorly rated one.

Frontal crash test results can't be used to compare vehicle performance across weight classes. That's because the kinetic energy involved in the frontal test depends on the speed and weight of the test vehicle. Thus, the crash is more severe for heavier vehicles.

Given equivalent frontal ratings, the heavier of two vehicles usually offers better protection in real-world crashes. In 2009, the Institute demonstrated this principle with a series of tests in which small cars with good frontal ratings were crashed into larger cars with good frontal ratings. Watch footage from these crash tests (2:33, opens in pop-up window).

For information about how ratings are kept up-to-date from one model year to the next, see the test verification page.

Tests lead to safer vehicles

When the Institute began its frontal offset tests, the majority of vehicles were rated poor or marginal. Today, the vast majority of vehicles earn good ratings.

It's no mystery why vehicles perform better today. Occupant compartments are much stronger than they used to be. They hold up in a crash and allow safety belts and airbags to do their jobs

Manufacturers have made these improvements in large part in response to the Institute's testing program. They know consumers consult the ratings before buying, so they design vehicles with our tests in mind, and that, in turn, leads to better outcomes in real-world crashes.