ARLINGTON, Va. — The Toyota Camry and Honda Accord equipped with optional side airbags are the only inexpensive midsize cars to earn good ratings in side impact crash tests conducted by the Insurance Institute for Highway Safety. The Chevrolet Malibu with optional side airbags is rated acceptable. Ten other midsize car designs earned the lowest rating of poor. The test simulates what happens when a pickup or SUV strikes a passenger vehicle in the side at 31 mph.
The Institute's side impact crash test represents what happens when a passenger vehicle is struck by a pickup truck or SUV.
The Camry, Accord, and Malibu without side airbags are rated poor for side impact protection. Other car models that earned poor ratings are the Suzuki Verona, Mazda 6, Dodge Stratus/Chrysler Sebring, Nissan Altima, Saturn L Series, Hyundai Sonata/Kia Optima, and Mitsubishi Galant. The Institute's side impact test results are a relatively new addition to the frontal offset crash test ratings the Institute has been providing to consumers since 1995. This is the first set of Institute side impacts involving cars.
"Manufacturers have made major improvements in the protection vehicles provide to occupants in frontal crashes," says Institute president Brian O'Neill. "Most new vehicles do well in the Institute's 40 mph frontal offset crash test. We believe this new test will drive similar improvements in protection for occupants in side crashes."
Side impacts are the second most common fatal crash type after frontal crashes. About 9,600 people were killed in side impacts in 2002, and in crashes between two passenger vehicles more driver deaths now occur in vehicles struck in the side than in the front. This contrasts with the past situation when there were many more deaths in frontal crashes.
"We simply haven't made the same progress in protecting people in side impacts as we have in frontal crashes," O'Neill points out.
Compared with federal test, Institute test produces higher risks for occupants of side-struck vehicles
In the Institute test, a moving deformable barrier strikes the driver side of a passenger vehicle at 31 mph. The barrier weighs 3,300 pounds and has a front end shaped to simulate the front end of a typical pickup or SUV. In each side-struck vehicle are two instrumented dummies the size of a short (5th percentile) female or a 12-year-old child, one positioned in the driver seat and one in the rear seat behind the driver. This is the first consumer test program to use a dummy that represents small women.
The federal government's side impact test uses a barrier representing a car's front end. In this test, there's no chance that the heads of the dummies in a struck vehicle will be hit by the intruding barrier. But in serious real-world side impacts, people's heads often are struck by intruding vehicles, especially if the striking vehicle is a pickup or SUV with a high hood. The Institute's barrier is taller than the government's to mimic the high hood heights of SUVs and pickups.
Top performers are Camry and Accord with side airbags
The Institute tested the Camry and Accord twice, with and without optional side airbags. (If a vehicle has side airbags as an option, the Institute's policy is to test the vehicle without the option. The manufacturer may request a second test with the optional airbags if it also reimburses the Institute for the cost of the vehicle.) In the tests of the Camry and Accord with side airbags, most injury measures for the front and rear passenger dummies were low. Both cars were equipped with side curtain airbags that deploy from the roof to protect people's heads plus torso airbags for the front-seat occupants.
"The Camry and Accord with side airbags are the only good performers in this group of midsize cars," O'Neill says. "The structure of the Camry did a reasonably good job of minimizing intrusion into the occupant compartment, and the curtain airbag prevented the dummies' heads from being hit by any hard structures, including the intruding barrier. The structure of the Accord didn't hold up quite as well as the Camry's, but injury measures were low and the Accord also earns the highest rating of good. Neither of these vehicles was quite good enough to earn a 'best pick' for side impact protection."
In contrast, the performances of the Camry and Accord without side airbags were poor. The heads of the driver dummies were struck by the intruding barrier, resulting in high injury measures.
"In a real-world crash of similar severity without side airbags, there would be a high likelihood of serious head injuries and rib fractures," O'Neill says. "In contrast, occupants of the Camry and Accord with the optional airbags would be much more likely to survive a severe crash like this without serious injuries."
Malibu with side airbags is rated acceptable
The Malibu's performance wasn't as good as the Camry's or Accord's, so this car earned the Institute's second highest rating in the side impact test. "The optional curtain airbag did a good job of reducing the injury measures recorded on the dummies' heads, but the torso injury measures for the driver dummy were too high and there was too much intrusion," O'Neill points out.
Vehicle side structure should prevent intrusion
There were major differences in how the structure of the sides of the cars performed in the test.
"In frontal crashes, well-designed vehicles have front ends that crumple to absorb energy and strong occupant compartments that resist intrusion," O'Neill explains. "This allows restrained occupants to be decelerated without injury. In contrast, there is virtually no crush space on the sides of vehicles. So in serious side crashes some intrusion is inevitable, but it should be minimized."
The Mitsubishi Galant had the best structural performance in this group of cars the Institute tested. The sill along the bottom of the doors wasn't severely crushed by the barrier, and B-pillar intrusion was less than in the other cars in this group. Still, the Galant earned a poor overall rating, largely because it lacked a side airbag to protect the driver's head and torso protection was poor. In contrast, the Dodge Stratus had the poorest performing structure. The sill below the doors was severely crushed, and there was major intrusion of the B-pillar. This contributed to high injury measures for the dummies.
2004 MITSUBISHI GALANT: GOOD STRUCTURE
There was much less intrusion into the side of the Galant (above) than into the Stratus (right). Measured displacement of the B-pillar (below) indicates it didn't intrude significantly into the driver's space. But the overall rating is poor primarily because the driver dummy's head and torso weren't well protected.
2004 DODGE STRATUS: POOR STRUCTURE
The striking barrier intruded much farther into the side of the Stratus (above) than into the Galant (left). Measured displacement of the B-pillar (below) indicates it was pushed well into the vehicle. With this much intrusion there's a lot less room for restraints to protect the occupants.
"To do really well in this test, vehicles need to have both side structures that resist major intrusion and side airbags that protect occupants' heads," O'Neill says.
Which cars have side airbags? What kind?
|Toyota Camry||optional torso airbag + side curtain|
|Honda Accord||optional torso airbag + side curtain|
|Chevrolet Malibu||optional side curtain|
|Mitsubishi Galant||optional torso airbag|
|Hyundai Sonata/Kia Optima||standard combination torso/head airbag|
|Saturn L Series||standard side curtain|
|Nissan Altima||optional torso airbag + side curtain|
|Dodge Stratus/Chrysler Sebring||optional side curtain|
|Mazda 6||optional torso airbag + side curtain|
|Suzuki Verona||side airbags aren't available|
Side airbags for short as well as tall people
The head of the driver dummy in the Saturn brushed past the standard side curtain airbag and was struck by the intruding barrier.
"Side curtain airbags need to cover enough of the window area to prevent people's heads from sliding underneath or around them," O'Neill points out. "Even though the head injury measures on the driver dummy in the Saturn weren't high, head contact with intruding objects should be prevented. The Saturn airbag doesn't do this for shorter occupants."
Sonata earns poor rating even though side airbag provided good head protection
The Hyundai Sonata has standard combination torso/head airbags that deploy from the side of the seats to protect the driver and front passenger. The side airbag for the driver did a good job of protecting the dummy's head, but there was major intrusion into the occupant compartment and high injury measures on the dummy's torso and pelvis.
The rest of the cars in this group the Institute tested also earned poor ratings. They had poor or marginal structures, and high injury measures were recorded on one or both of the dummies' heads and bodies.
Side airbags are reducing risks in real-world crashes
Recent Institute research shows that side airbags with head protection are reducing deaths by about 45 percent among drivers of cars struck on the driver side. Side airbags that protect the chest and abdomen, but not the head, also are reducing deaths but are less effective (about a 10 percent reduction in deaths). Before the availability of head-protecting airbags, there was virtually nothing to prevent people's heads from being struck by intruding vehicles or rigid objects like trees or poles in serious side impacts.
"Our crash test results confirm what the Institute found is happening in real-world crashes," O'Neill says. "Side airbags designed to protect people's heads can prevent very serious head injuries. For the most part, vehicles with side airbags for the head are performing better in the Institute's test. We expect this test to result in more vehicles equipped with side airbags as standard equipment."
Front versus side impacts: driver deaths in cars 1-3 years old, per million cars registered
| ||Calendar years|| |
|Crash type||Impact direction||1980-81:||1990-91:||2000-01:||Change: |
|All car crashes||Front||86||52||62||53||41||46||-52%|
|Car struck by other |
|Source: Fatality Analysis Reporting System, National Highway Traffic Safety Administration|
Bigger share of the crash problem
Driver death rates in frontal crashes declined by about half from 1980- 81 to 2000-01. Meantime, reductions in death rates in side impacts haven't been as dramatic. The result is that during 2000- 01 side impacts accounted for 37 percent of driver deaths overall, up from 26 percent in 1980-81. In crashes involving a car and another passenger vehicle, about half of the car driver deaths in 2000-01 occurred in side impacts. This compares with about a third of the deaths during 1980- 81. This is because of significant improvements in frontal crash protection without corresponding improvements in side impact protection. For example, frontal airbags are standard in new vehicles. The structural designs of vehicles are better than they used to be. More motorists are using safety belts, which are more effective in frontal crashes than in side impacts.
Growing sales of SUVs and pickup trucks have exacerbated height mismatches among passenger vehicles, and these mismatches increase the risk of serious head injuries among occupants of side-struck vehicles. The effect of the changing vehicle mix and changing risks for occupants in struck vehicles is apparent in the fact that 70 percent of driver deaths in passenger vehicles struck on the driver side by other passenger vehicles during 1980-81 occurred when the striking vehicle was another car. Thirty percent occurred when the striking vehicle was a pickup or SUV. By 2000-01 these percentages had almost reversed. Fifty-seven percent of the car driver deaths involved striking pickups or SUVS, and as the numbers of SUVs and pickups continue to increase so will this percentage.
Driver deaths in passenger vehicles 1-3 years old struck on the driver side
by other passenger vehicles, by type of striking vehicle
| ||Calendar years|
|SUV or pickup||30%||40%||57%|
|Number of deaths in struck vehicles||634 ||751 ||616 |
|Source: Fatality Analysis Reporting System, National Highway Traffic Safety Administration|
How vehicles are evaluated in the Institute's test
Each vehicle's overall side impact evaluation is based on injury measures recorded on the two instrumented SID-II dummies, assessment of head protection countermeasures, and the vehicle's structural performance during the impact.
Injury measures are obtained from the two dummies, one in the driver seat and the other in the rear seat behind the driver. These measures are used to determine the likelihood that the driver and/or passenger would have sustained serious injury to various body regions. Measures are recorded from the head, neck, chest, abdomen, pelvis, and leg. These measures, especially from the head/neck and torso (chest and abdomen), are major components of each vehicle's overall evaluation.
To supplement head injury measures, the movements and contacts of the dummies' heads during the crash are evaluated. This assessment is more important for seating positions without head-protecting airbags, which (assuming they perform as intended) should prevent injurious head contacts. Very high head injury measures typically are recorded when the moving deformable barrier hits a dummy's head during impact. But a "near miss" or grazing contact also indicates a potential risk of serious injury in a real-world crash. This is because small differences in occupants' heights or in their seating positions compared with the test dummies could result in a hard contact and high risk of serious head injury. In the rear seat, the potential for serious injury is influenced by whether the seating position puts occupants' heads in proximity to areas designed with padding or something else to reduce impact forces versus areas with hard or unprotected structures. Analysis of the movement and contact points of the dummies' heads during the side impact crash test is used to assess this aspect of protection.
Structural performance is based on measurements indicating the amount of B-pillar intrusion into the occupant compartment. Some intrusion into the compartment is inevitable in serious side impacts. Any intrusion that does occur should be uniform both horizontally and vertically and shouldn't seriously compromise the driver or passenger space.
These three factors are evaluated in the Institute's side impact tests — driver and passenger injury measures, head protection, and structural performance — to determine each vehicle's overall side crashworthiness evaluation.