| In 1978 the U.S. National Highway Traffic Safety Administration
(NHTSA) began crash-testing popular vehicle models
in the United States. Their protocol (FMVSS 208) involved running vehicles
head-on into a fixed barrier at 35 mph. Results were
published for the information of consumers, as the US arm of the international New Car Assessment Program
(NCAP). Today's passenger vehicles are designed to be
more crashworthy than they used to be, largely thanks to this
testing. Still, over 30,000 occupants die in crashes on U.S. roads each year.
The very success of the NCAP means remaining differences
in performance among most new vehicles in full-width tests
are small. This doesn't mean important crashworthiness differences
no longer exist. They do exist, and additional crash test
configurations can highlight these differences. One such test
is the Insurance Institute for Highway Safety's (IIHS)
frontal offset crash. Full-width and offset tests complement
each other. Full-width tests are especially demanding of restraints
but less demanding of structure, while the reverse is true
in offsets.
Full-width frontal impact crash test - NHTSA and OSA
currently use this procedure for their full-width frontal
impact collisions. Dummies are seated in the driver's
and front passenger seat. The vehicle crashes head-on
into a rigid concrete barrier at 35 mph (56 km/h). Afterwards, researchers measure and
evaluate the impact on the dummies' head, chest, and legs.
This test provides very high deceleration forces to the
test dummies and is particularly well
suited to the evaluation of occupant restraint systems
such as seat belts and air bags. Of note, however, the
damage done to the vehicle itself is not assessed.
Full-width frontal
crash-test rating categories: Chance of life-threatening injury
|
Less than 10% chance (5 stars) |
|
10-19% chance (4 stars) |
|
20-34% chance (3 stars) |
|
35-45% chance (2 stars) |
|
More than 45% chance (1 star) |
NHTSA's Star Ratings - In 1994, the U.S. National Highway Traffic Safety Administration
(NHTSA) changed the way they rated frontal crash
test performance. Instead of the confusing numerical scale
they had used, NHTSA
converted to a five-star rating system. Crashtest.com
converts the NHTSA
full-width frontal impact star ratings into our color-coordinated
system as shown in the chart above.
Side Impact - In 1996, NHTSA added testing for side-impact
protection. For side-impact testing, NHTSA
runs a 3,015 lb moving trolley into the driver's side of a
car representing a typical intersection-type collision.
As with frontal impact testing, the side impact test is
conducted at five mph above the federal standard, which means
the trolley hits the car at 38.5 mph. Crashtest.com
converts the NHTSA
Side Impact star ratings into our color-coordinated
system as shown in the chart below.
Side Impact Crash-Test Rating Categories: Chance
of Life-Threatening Injury
|
Less than 6% chance (5 stars) |
|
6-10% chance (4 stars) |
|
11-20% chance (3 stars) |
|
21-25% chance (2 stars) |
|
More than 25% chance (1 star) |
Crashtest.com converts the NHTSA
full-width frontal impact star ratings into our color-coordinated
system as shown in the chart above.
Impact Angle Data - Statistics vary greatly from year-to-year and source-to-source,
but we've averaged the available data to come up with this
angle of impact chart. This chart denotes all collisions,
not just fatal or injury-producing incidents.
USNCAP Testing Needs Revision - The NHTSA testing regimen remains virtually
the same now, 23 years later, as when it began. The only major
addition has been a side-impact test (adopted from the Euro-NCAP
side-impact test).
Recent testing by the International NCAP Agencies has
shown that the the full-width frontal crash test does not
show how effectively a vehicle's safety cage or occupant restraint
systems will protect the occupants of a vehicle in real-world
collisions. It is possible for a NHTSA test to result in "good" head and chest injury
measurements (and therefore a good star rating) even though
the structure performs poorly or becomes unstable. In
these cases the risk to life in a slightly different crash
configuration, or slightly higher speed, could result in a
much higher risk of serious injury.
In the US, mandatory airbag legislation has substantially equalized
the testing results of most full-width collisions. For example,
ALL of the vehicles tested by the NHTSA in the past few years have
earned a minimum of 3 stars in their full-width collision.
With no significant variation in results, it's significantly
harder for consumers differentiate between vehicles.
In summary, the US NCAP needs to adopt a more modern method
of testing. Australia has already abandoned the NHTSA
full-width test and has gone
with the Euro
NCAP (EEVS) system. Adoption of the IIHS
or European EEVS testing system is clearly indicated in the
case of the US NCAP (NHTSA).
A new report detailing the latest proposals for updating
the FMVSS 208 test procedures has just been published. Please
read (in pdf) "Updated Review of Potential Test Procedures
for FMVSS 208 - October 1999"
Read the Advocates For Highway And Auto Safety
Report from September 16th 1999: Stuck in Neutral: Recommendations For Shifting
The Highway And Auto Safety Agenda (PDF version here)
For further information on current US DOT Crashworthiness
Rulemaking Activites consider reading the following DOT reports:
1. Status Report on Establishing a Federal
Motor Vehicle Safety Standard for Frontal Offset Crash Testing
- April 1997 | 2. NHTSA Plan for Achieving Harmonization
of the U.S. and European Side Impact Standards - April 1997
| 3. Status of NHTSA Plan For Side Impact Regulation
Harmonization and Upgrade - March 1999 | 4. Advanced air bag safety standard proposal
notice (To take full effect in 2005) | 5. Identification of Issues Relevant to Regulation,
Design, and Effectiveness of Head Restraints - November 1996
| 6. Status Report on Establishing a Federal
Motor Vehicle Safety Standard for Frontal Offset Testing -
April 1997
For further information on International NCAP test procedures
please consider reading the following research papers presented
by Australian safety engineer Michael Paine: 1. Consumer Crash Tests: The Elusive Best
Practice | 2. Offset Crash Tests | 3. Guidelines for Crashworthiness Rating Systems
US Residents - If, after reading these documents, you feel (as we
do) that the US DOT is dragging their feet, write to your
US Senator and Congressman. |
