Getting America to Buckle Up
Seat belts still the best way to save lives

Any story about occupant safety in automobiles in the U.S. is a story about seatbelts, which are the single most effective motor vehicle occupant safety device yet developed for older children and adults. In addition to seatbelts, key safety devices that protect occupants include child safety seats as well as innovations in car design and technology, such as:

• Airbags

• Collapsible steering columns

• More forgiving interior designs

• Shock-absorbing bumpers

• Headrests

• Shatter-proof safety glass

 
Outside of the car, safety is significantly affected by the highway design features and the roadside design.  Some examples of good roadside design features for highways are:

• Traversable shoulders and roadsides

• Wide, traversable medians

• Break-away sign and light posts

• Impact attenuators (crash cushions) in front of fixed rails and bridge abutments

• Guard rail to redirect errant vehicles

 

Increasing compliance
Seat belt use in the U.S. is at an all-time high, with some 70% compliance nationwide. California's rate of over 91% is among the best in the nation. Because the state has such a large population, every additional percentage point of occupants who use seat belts translates into a large number of deaths and injuries avoided. As a result, efforts to get more people buckled up will continue.

 
Examining what efforts have worked can provide guidance for developing strategies to achieve greater compliance. This combination of policy, enforcement and education is key to California’s success.

Research suggests that the single most promising tactic to boost compliance are so-called primary seat belt laws, which allow a traffic stop to be made solely on the basis of an officer's observation that an occupant is not belted. However, the primary seat belt law needs support from enforcement to achieve results. Media campaigns and community outreach are used to spread awareness of the laws and enforcement efforts.
 

In California, which passed a primary enforcement law in 1993, compliance rose from 71 percent to 83 percent in the first year, and other states that switched from secondary to primary experienced similar increases. Compliance in California continued to rise until it plateaued at its current level. The state's fatality rate fell by 34 percent, while one national study put the reduction nationwide at 20 percent for all states with primary laws.

 
Fewer than half the states—19—have this type of law. The rest consider riding unbelted as a secondary matter, enforceable only if an officer stops a vehicle on suspicion of a primary violation.  Several states with primary enforcement laws continue to have lower seat belt use than some states with secondary enforcement laws. The disparity is due to how well the laws are actually enforced, the public's awareness of the laws and whether the law applies to all occupants or just those in the front seat.

 
Echoing the debate over original seat belt requirements that took place some 40 years ago, opponents of primary enforcement cite concerns about undue police intrusion into drivers' privacy, and a fear that the added enforcement might magnify existing unfair practices, such as stopping members of racial and ethnic minority groups in disproportionate numbers. They argue that the gains are not worth those risks, because progress is being made under the secondary laws.

 

Measuring seatbelt use and assessing risk
There is no single way to measure seatbelt use. but there are three methods that most often cited. They are:

• The National Occupant Protection Use Survey, conducted by the National Highway Traffic Safety Administration (NHTSA); the survey is made up of three different studies in which seatbelt use is observed directly under different conditions; it was begun in 1992 and has been carried out every two years since;

• The Motor Vehicle Occupant Safety Survey, a telephone survey conducted by NHTSA; and

• NHTSA’s standardized annual statewide observed seat belt usage survey.

 

A number of elements are used to assess occupant risks.

• Fatalities are the most reliable measure of occupant harm, in part because injuries are difficult to compare across data sources, because there is no common standard for ranking their severity. To measure fatalities, NHTSA takes fatal crash data from every state and enters it into a standardized form comprised of 100 coded elements. This makes up the Fatality Analysis Reporting System.
   

• The National Automotive Sampling System is in two parts. One part is the Crashworthiness Data System, which contains detailed information drawn from police reports of crashes selected randomly from around the country. The data includes information on damage to the vehicle, occupants' injuries, the cause of the crash and conditions at the time of the crash. The second part is the General Estimates System that gathers less information about each crash, but examines a larger number of them to give a broader picture.

 

From Tin Lizzies to Fighter Jets: A Brief History
Seat belts in the U.S. date back to practically the first automobiles, when owners installed them not for protection in crashes but to keep themselves from falling out. American automakers began including seatbelts in their new models after World War II—the first being in the 1950 Nash Statesman and Ambassador models—but buyers weren't impressed because they were uncomfortable and hard to use.
 

A significant development in making belts more comfortable and more effective came in 1958 when Swedish engineer Nils Bohlin patented the three-point belt while doing research for Volvo. He adapted his design from harnesses used by military pilots. Today's seat belts have been refined further and continue to be fine-tuned with devices such as pre-tensioners, which eliminate slack in the belt milliseconds after the initial impact, and webbing that pays out slack to prevent excessive decompression of the passenger's body. Four-point belts are about to be offered in a few models as well.

 
Belts work as a restraint by both keeping passengers in their cars during a crash and by lessening the impacts they suffer inside the vehicle. During a crash, three distinct events occur. The first is the collision of the vehicle with another object. The second is the collision of the occupant’s body with the interior of the vehicle (including the seatbelt). The third is the occupant’s internal organs colliding against the body’s skeletal structure. A seatbelt functions to stop or counteract the forces generated by these collisions.
 

First, the belt stops the occupant along with the car, preventing or reducing collisions with the interior. The seatbelt also spreads the energy from the sudden deceleration over the larger, stronger parts of the body, namely, the pelvis, chest, and shoulders, which are more able to absorb the energy without suffering injury. This also helps reduce injuries to internal organs. Seatbelts are also important in their original role: keeping the occupant from leaving the car as a result of a crash. Seventy-five percent of occupants ejected from the car are killed. Overall, the National Highway Traffic Safety Administration reports that seatbelts reduce a person’s chances of dying in a crash by 45% and being injured by 50%.
 

Injuries from motor vehicle crashes are the most costly and most-often fatal form of accidental injury. Seatbelts are important in that equation because people who wear them have less severe injuries. Crash victims without seat belts are four to five times more likely to suffer serious injuries than belted ones. That translates into higher medical costs. The average inpatient charge for an unbelted victim is more than 60% higher than for a belted one.
 

The National Highway Traffic Safety Administration estimates that between 1975 and 2000, seat belts saved over 135,000 lives–12,000 in 2000 alone. Seatbelt use has risen over the years, which accounts for the larger number of lives saved in later years. If all vehicle occupants used seatbelts, more than 9,000 additional people, or roughly one-quarter of those killed, could have been saved in 2000.

 
Today's regulatory framework affecting seatbelt use dates back to the late 50s and early 60s, when public health advocates convinced policymakers and legislators of the need to address traffic safety as a health issue, not just an engineering matter. Several years of well-publicized debates, climaxing with the 1965 publication of Unsafe at Any Speed, Ralph Nader's critique of auto industry engineering practices, led to federal legislation that incorporated parts of the new approach. 
 

In 1966, Congress passed a law creating today's Department of Transportation and two acts that form the basis for most traffic safety efforts in the U.S. today, the Highway Safety Act and the National Traffic and Motor Vehicle Safety. The legislation authorized the federal government to regulate the safety of motor vehicles, including requiring that seatbelts be installed in new cars at the factory. The legislation also created the National Highway Safety Bureau, the National Highway Traffic Safety Administration's precursor.

Federal law required shoulder belts to be installed in the front seat of new cars starting in 1968, but the availability of seat belts did not guarantee that occupants would use them. Political resistance to laws requiring their use was strong. Most drivers were not convinced they were desirable or necessary. In 1981, 15 years after the landmark highway safety bills, seat belt use was a mere 11 percent, according to the Centers for Disease Control. It had risen to 14 percent in 1983.
 

In 1984, the National Highway Traffic Safety Administration proposed a regulation that would create pressure on states to regulate seat belt use and resolve a debate that had been raging for nearly 15 years among federal policymakers and safety advocates over whether to require cars to be equipped with automatic restraints, which would mean automated seatbelts or air bags, the only two technologies available at the time. The federal law gave states five years to enact mandatory seat belt laws as an alternative to federal rules requiring automatic restraints. If enough states passed seat belt laws to cover at least two-thirds of the country's population by September 1989, the automatic restraint provisions would not go into effect.

 

In 1984 New York became the first state requiring the use of seatbelts, but only for front seat passengers. In 1978, Tennessee had passed the first state law requiring children to be restrained, as a result of a long campaign by a leading medical expert in the state. By 1985, some kind of child restraint laws were on the books in all states, and laws for adults had been introduced (if not passed) in nearly all. By the September 1989 deadline, 34 states had passed seat belt laws, and the two-thirds threshold was achieved. Today, all but one have laws for adults.

 
The dual federal mandate had led the auto industry to concurrently develop and begin including passive restraint systems in some car models. Eventually, in 1981, airbags were made mandatory, starting with phased-in requirements for new cars produced in successive model years ending in the 1997 year when all new cars would have to offer them to both front-seat occupants. By 1996, there were an estimated 42 million cars on the road with some kind of airbag system, more than two-thirds dual-side.

 
Since 1998, the national rate of seat belt use has stalled at roughly 70 percent. In the mid- to late 90s, the National Highway Traffic Safety Administration set a goal of 85% by 2000 and 90% by 2005. The current campaign has lowered the goal to 78% by 2003. "Buckle Up America" is a national education campaign, which is linked with "Click It or Ticket," statewide campaigns that use high intensity enforcement coupled with paid media informing the public about those law enforcement mobilizations.
 

The U.S. Department of Transportation continues to press the need for primary enforcement. In a report released in October 2000, the inspector general stated: “Unless additional states enact and enforce primary laws, which are the most effective means of increasing seatbelt use, we see no credible basis to forecast increases in excess of the recent trend."

 

Related Links:

Summary of California Occupant Protection Laws
(PDF, 96KB)

Trends in Occupant Restraint Use and Fatalities
 

Fatality Analysis Reporting System (FARS)
 

The Buckle Up America Campaign
 

Click It or Ticket Campaign

http://www.iihs.org/safety_facts/state_laws/restrain.htm – Insurance Institute for Highway Safety regularly updates this summary of states’ seatbelt and child restraint laws.

http://www.nsc.org/public/arts.pdf – National Safety Council’s “Mired in Mediocrity: A Nationwide Report Card on Driver and Passenger Safety” assesses the current strength and effectiveness of occupant protection laws in each state.

http://www.nhtsa.dot.gov/people/injury/airbags/presbelt – “The Presidential Initiative for Increasing Seat Belt Use Nationwide: Recommendations from the Secretary of Transportation” outlines the national goals and strategies to increase seatbelt use that guide current efforts. 

http://www.driverstechnologyassociation.co.uk/seatbelts.htm – A brief seatbelt history timeline.

 

 

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