Consumer Response to Seat Belt Use Campaigns and Inducements: Implications For Public Health Strategies

Leon S. Robertson, Insurance Institute for Highway Safety
ABSTRACT - Efforts to reduce motor vehicle deaths and injuries in the U.S. recently have concentrated on belt use advertising campaigns, buzzer-light reminder systems and starter-interlock belt systems in cars. Carefully controlled studies of advertising campaigns find no effect on belt use. The buzzer-light system had no effect and the interlock's effect was temporary and provoked adverse consumer reaction. Strategies requiring no action by the person to be protected have been available but neglected.
[ to cite ]:
Leon S. Robertson (1976) ,"Consumer Response to Seat Belt Use Campaigns and Inducements: Implications For Public Health Strategies", in NA - Advances in Consumer Research Volume 03, eds. Beverlee B. Anderson, Cincinnati, OH : Association for Consumer Research, Pages: 287-289.

Advances in Consumer Research Volume 3, 1976      Pages 287-289

CONSUMER RESPONSE TO SEAT BELT USE CAMPAIGNS AND INDUCEMENTS: IMPLICATIONS FOR PUBLIC HEALTH STRATEGIES

Leon S. Robertson, Insurance Institute for Highway Safety

ABSTRACT -

Efforts to reduce motor vehicle deaths and injuries in the U.S. recently have concentrated on belt use advertising campaigns, buzzer-light reminder systems and starter-interlock belt systems in cars. Carefully controlled studies of advertising campaigns find no effect on belt use. The buzzer-light system had no effect and the interlock's effect was temporary and provoked adverse consumer reaction. Strategies requiring no action by the person to be protected have been available but neglected.

In the U.S. injuries in motor vehicles are the leading cause of death of persons aged 1-35 years. More than half of traumatic spinal cord lesions that result in paralysis occur in motor vehicle crashes (Kraus, et al., in press). About 3,927,000 motor vehicle related injuries were estimated from the National Health Survey in 1973 - almost 1 in every 50 U.S. residents (Health Resources Administration, 1974). Motor vehicle occupants sustain about three-fourths of fatal injuries with the remainder distributed among pedestrians, motorcyclists, and bicyclists.

The incidence and severity of vehicle occupant injuries would be reduced substantially if people would use seat belts and shoulder harnesses available in most cars and some other vehicles. However, attempts to increase belt use have had, at best, temporary and, usually, no success.

MEDIA CAMPAIGNS

We all remember the "Buckle Up for Safety" and similar sloganeering campaigns in electronic and print media. Until recently these campaigns were launched with no precampaign experimentation to estimate potential effectiveness. Evaluation of effectiveness was limited to before and after claimed use in questionnaire surveys in a few cases. However, a 1969 study compared actually observed belt use with claimed use and found that claimed use exceeded actual use substantially (Waller and Barry, 1969). That type of error plus the lack of control groups in earlier studies led to the conclusion that the effect of media campaigns was unknown. A 1970 survey of drivers actually observed in their cars found only about 22 percent use of any belts in late model (1968-71) cars in metropolitan areas, less in older cars in metropolitan areas, and less than 10 percent use in small cities (Robertson, et al., 1972). It was evident that if earlier campaigns had any effects at all, a large potential for reduced injury through increased belt use remained.

Based on correlates of belt use in the 1970 study, six television messages were produced, each directed at a specific audience. One was judged best among 30 public service entries in the TV-Radio Advertisers Club of Philadelphia competition and another was among 10 finalists in 400 entries to the public service competition of the Advertising Club of New York. By arrangement with advertisers and a cable television company, messages were shown in prime time on one cable of a split cable system designed for test marketing. The households on the cables are distributed on alternate streets in such a way that classical experimental-control design was achieved.

Each message was shown during programs appealing to audiences that were the targets of the messages (children, teenagers, fathers and mothers). The messages were shown 943 times over a period of nine months - the equivalent of a $7 million campaign on a national basis.

Daily belt use observations were conducted on a rotation basis among sites throughout the test city for 1t months, including one month prior to and one month after the campaign. Belt use observations were matched to experimental and control cables by matching vehicle license numbers to motor vehicle administration files, obtaining owner names and addresses, and subsequently matching these names and addresses to those in cable company files. The observers did not know the purpose of the study and the people in the community did not know about the split cable system. Thus, a double-blind experiment was accomplished.

Comparison of belt use by drivers from households on the experimental and control cables, as well as with those on neither cable, revealed no effect on belt use of the television campaign (Robertson, et al., 1974). Similar results were obtained in a separate study using radio and television in some communities and none in others (Fleischer, 1972). Unless and until a rigorously designed study demonstrates otherwise, there is formidable evidence leading to the conclusion that mass media campaigns are ineffective means to increase belt use.

MECHANICAL INDUCEMENTS

The federal agency responsible for reducing motor vehicle related injuries, the National Highway Traffic Safety Administration (NHTSA), attempted to require "passive" protection for vehicle occupants in 1972 and later model vehicles in frontal barrier crashes up to and including 30 miles per hour. "Passive" public health strategies refer to those approaches that do not require each individual to take action to protect himself (Haddon and Goddard, 1962). Passive protection is automatic - as in purified water, pasteurized milk, shielded electrical cables, fuses and circuit breakers in electrical systems, and inflatable air cushions in severe motor vehicle crashes.

Car manufacturers opposed the proposed federal requirement for passive vehicle occupant protection. The standard was then revised to allow a buzzer-light belt use reminder system as an alternative, optional to the manufacturers. With the exception of a few thousand cars equipped with inflatable air cushions, all cars manufactured for sale in the U.S. from January 1, 1972 through August 14, 1973 were equipped with the buzzer-light system. However, a study in the spring and summer of 1972 found no statistically significant difference in observed belt use between 1972 model year cars with and those without the buzzer-light system (Robertson and Haddon, 1974).

This study was also double blind. The observers did not know the purpose of the study and drivers did not know belt use was being observed. Cars with and without buzzer-light systems were identified by matching license numbers to vehicle identification numbers in motor vehicle administration files.

Two marketing studies of the buzzer-light system prior to its requirement claimed that it was effective in increasing belt use. However, one study was based on questionnaires from government employees using government owned cars in which belt use was mandatory by administrative directive (Perel and Ziegler, 1971). The second study involved a 30 day test drive by drivers who previously claimed not to use belts in a telephone survey. These drivers were given "intensive introduction to the vehicle, complete with test drive and a thorough explanation of the operation of all features which it contained" (Shaw, 1971). After 30 days, an interviewer took a drive with the driver and observed belt use. Apparently the researchers unknowingly rediscovered the Hawthorne effect.

Cars manufactured for sale in the U.S. after August 14, 1974 were required - if the manufacturer chose not to install the specified passive protection - to install a system that would not allow the car to start if front seats were occupied by more than a certain weight and belts were not extended or latched. Again, with the exception of a few thousand air cushion equipped luxury models, the so-called interlock belt use system was installed in 1974 model year cars.

Initially belt use was found to be nearly 60 percent in interlock equipped vehicles (Robertson, in press). A survey of owners of 1974 cars found only 29 percent mentioned the interlock among the three features liked least about their new cars (Robertson, 1975a). However, many of this minority objected strongly (Congressional Record, 1974). Letters to congressmen resulted in the enactment of a federal law, subsequently signed by the President, banning the interlock as well as continuous buzzer-light systems.

In the spring of 1975 a survey involving observed belt use in four metropolitan areas found that two-thirds of drivers in 1974 and 1975 model cars were not using any belts and only 27 percent were using shoulder harnesses in addition to lap belts (Robertson, t975b). Because of lower use in small cities and towns, lower use among children, and lower use in cars as they get older, the use of belts over the lifetime of these cars will be less than 20 percent.

MANDATORY BELT USE LAWS

Another means proposed to increase belt use in the U.S. is to enact laws requiring use. A few countries now have such laws following their reported effectiveness in Australia. Belt use increased to more than 60 percent in rural areas and 70 percent in urban areas in the first year following enactment of a mandatory use law in the state of Victoria. This increase was accompanied by a 21 percent reduction in vehicle occupant fatalities in metropolitan areas and a 10 percent reduction in rural areas (Foldvary and Lane, 1974). Whether the initial belt use achieved can be maintained over the long run remains to be seen.

The only U.S. jurisdiction thus far that enacted a belt use law, Puerto Rico, had only a small, temporary increase in use. After reaching a maximum of 24 percent, public reaction resulted in a reduction in the penalty for conviction and belt use fell to 10 percent (Insurance Institute for Highway Safety, 1975). Despite endorsement by the major auto manufacturers, belt manufacturers, NHTSA, state and national safety councils, and others, no state in the U.S. has enacted a mandatory belt use law. Enactment by a large number of states, much less enforcement of and compliance with such a law, remains problematic.

PUBLIC HEALTH STRATEGIES

The history of public health suggests that attempts to control damage to human beings by changing everyone's behavior is never completely successful. Even when the behavior is required by law or administrative directive, such as immunizations to enter school, compliance seldom exceeds 80 percent. Campaigns to increase examination for problems such as cervical cancer seldom achieve more than 50 percent success (Robertson and Heagarty, 1975). And, as I have noted, changing behaviors that involve frequent attention and inconvenience such as belt use, is especially difficult.

With present technology, behavior change strategies may be the only ones available for some public health problems. However, by focusing on behavior change, we have sometimes delayed the adoption of available alternative strategies or neglected their development. In the case of motor vehicle occupant crash protection, consumers have been needlessly badgered by slogans, buzzers, lights, and interlocks while alternative passive approaches were left on the shelf.

The air cushion that inflates automatically in a severe crash, gently controlling the deceleration of occupants, is but one of a number of such approaches. The air cushion system has been installed in more than 8,000 cars that have now accumulated well over 100 million miles of on-the-road travel. Hundreds of laboratory tests have been done and more advanced systems than those now on the road are available. Only two inadvertent deployments have occurred while the vehicles were being driven, causing only minor injury. More than 1,000 minor crashes have occurred in which the air cushion did not deploy. In severe crashes where the vehicle was towed away, death or life threatening injury occurred in less than 3 percent of occupants of air cushion equipped vehicles compared to 5 percent using belts in belt equipped cars and 11 percent not using belts in similar cars in similar crashes (Robertson, 1975b).

Yet how many consumers know about the availability of these air cushion systems? Only token advertising marked their introduction with little or no follow-up. A film demonstrating their effectiveness and convenience was shown to dealers but was not even made available to the public.

Other passive approaches have been neglected as well. Our roadsides are lined with trees, poles and other solidly built structures that should be removed or modified to yield gently when they are hit by vehicles that stray only a few feet from the roadway. At the same time most of our vehicles are unnecessarily capable of speeds twice the national 55 mile an hour speed limit at a waste of scarce fuel and raw materials as well as lives.

Does it make sense to continue mainly to attempt to change every individual's behavior whether by advertising, education, or law enforcement? Or does it make more sense to force decision makers to provide automatic protection where the technology is available to do so? If faced with the choices today, would we purify water at the source or would we launch an ad campaign to attempt to persuade everyone to boil his or her drinking water? Would we require pasteurization of milk before it is sold or would we pass a law that each family had to boil their milk before it is consumed? The choices we face today with respect to motor vehicle injuries, as well as other public health problems, are no different than these.

REFERENCES

Congressional Record, "Motor vehicle and schoolbus safety amendments of 1974," (August 12, 1974), H8119ff.

G. A. Fleischer, An Experiment in the Use of Broadcast Media in Highway Safety (Los Angeles: Department of Industrial and Systems Engineering, University of Southern California, 1972).

L. A. Foldvary and J. C. Lane, "The Effectiveness of Compulsory Wearing of Seat-Belts in Casualty Reduction,'' Accident Analysis and Prevention, 6 (September, 1974), 59-81.

W. Haddon, Jr. and J. L. Goddard, "An Analysis of Highway Safety Strategies," In Passenger Car Design and Highway Safety (New York: Association for the Aid of Crippled Children and Consumers Union of the U.S., 1962).

Health Resources Administration, Current Estimates from the National Health Survey, United States - 1973 (Washington, D.C.: U.S. Government Printing Office, 1974).

Insurance Institute for Highway Safety, "Belt Use in Puerto Rico," Status Report, 10 (May 12, 1975), 4.

J. F. Kraus, et al., "Incidence of Traumatic Spinal Cord Lesions," Journal of Chronic Diseases, in press.

M. Perel and P. M. Ziegler, An Evaluation of a Safety Belt Interlock System (Washington, D.C.: National Highway Traffic Safety Administration, 1971).

L. S. Robertson, "Safety Belt Use in Automobiles with Starter-Interlock and Buzzer-Light Reminder Systems," American Journal of Public Health, in press.

L. S. Robertson, "Factors Associated with Safety Belt Use in 1974 Starter-Interlock Equipped Cars," Journal of Health and Social Behavior, 16 (June, 1975a) 173-177.

L. S. Robertson, "Motor Vehicle Occupant Restraint Use and Effectiveness in Real-World Crashes," Appendix A in testimony of W. Haddon, Jr. and A. B. Kelley before the National Highway Traffic Safety Administration, Public Meeting on Occupant Crash Protection, May 19, 1975b.

L. S. Robertson, et al., "A Controlled Study of the Effect of Television Messages on Safety Belt Use," American Journal of Public Health, 64 (November, 1974), 1071-1080.

L. S. Robertson and W. Haddon, Jr., "The Buzzer-Light Reminder System and Safety Belt Use," American Journal of Public Health, 64 (August, 1974), 814-815.

L. S. Robertson and M. C. Heagarty, Medical Sociology: A General Systems Approach (Chicago: Nelson-Hall Company, 1975).

L. S. Robertson, B. O'Neill, and C. W. Wixom, "Factors Associated with Observed Safety Belt Use," Journal of Health and Social Behavior, 13 (March, 1972), 18-24.

D. J. Shaw, "Interim Results from Test Drive I Advanced Features Study." Transmitted to Docket 69-7, National Highway Traffic Safety Administration, July 27, 1971.

P. F. Waller and P. Z. Barry, Seat Belts: A Comparison of Observed and Reported Use. (Chapel Hill: University of North Carolina Highway Safety Research Center, 1969).

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