Front Passenger Research Articles

Rear seat restraint system effectiveness in preventing fatalities

Restraint system effectiveness for rear seat adult (16 years or older) car occupants is estimated by applying the double pair comparison method to Fatal Accident Reporting System (FARS) data for 1975 through 1985. As this data set contains information on fatal crashes only, the results apply exclusively to fatalities, and should not be generalized to other levels of injury. Rear seat occupants coded as using any restraint system are assumed to be using the lap belt only. Occupants in all four outboard seating positions (that is, driver and right front passenger, right and left rear passengers) serve as “other” occupants. Disaggregating the “other” occupant by restraint use generates six estimates of restraint system effectiveness for each of the two rear outboard positions. Insufficient data precluded estimating effectiveness for the center rear (or center front) positions, and also use of these occupants as “other” occupants. Average restraint system effectiveness for the two outboard rear seating positions is estimated as (18 ± 9)%, where the error limit indicates one standard error. These estimates suggest that there is a 39 in 40 chance that rear lap belts reduce fatality likelihood, but a less than 1 in 10 chance that the reduction exceeds 30%.

The effectiveness of safety belts in preventing fatalities

The effectiveness of safety belts in preventing fatalities to drivers and right front passengers is estimated by applying the double pair comparison method to 1974 or later model year cars coded in the Fatal Accident Reporting System. The method focuses on “subject” occupants (drivers or right front passengers) and “other” occupants (any except the subject occupant). Fatality risks to belted and unbelted subject occupants are compared using the other occupant to estimate exposure. In this study, drivers and right front passengers are subject occupants; choosing other occupants differing in age, seating positions, and belt use, generated 46 essentially independent estimates of safety belt effectiveness. The weighted average and standard error of these is (41 ± 4)%. This finding agrees with the 40%–50% range reported in a recent major review and synthesis by the National Highway Traffic Safety Administration. Combining this with the present determination gives (43 ± 3)%; that is, if all presently unbelted drivers and right front passengers were to use the provided three point lap/shoulder belt, but not otherwise change their behavior, fatalities to this group would decline by (43 ± 3)%.

A Successful Program for Increasing Occupant Safety Belt Usage

In December of 1981 a survey of 10 Ford facilities throughout the United States showed that safety belt usage among Ford employees was about the same as the 1981 national average of about 11%. In view of this low usage, and convinced of the value of wearing safety belts, Ford began to look for ways to increase employee belt usage. In 1983, three Ford plants participated in pilot programs. A corporate committee, consisting of five volunteers, reviewed the results of these pilot programs and concluded that a corporate-wide program in 1984 should be conducted. The single most important aspect of the corporate initiative was to allow volunteer employees at each local facility to plan and administer a safety belt program best suited to their own needs. The corporate committee strongly recommended that two key elements of a program ought to be: (1) an “awareness” session in which employees were shown the value of wearing safety belts, and (2) distributions of small-valued incentives to assist in promoting the program. The corporate committee also requested that four observational surveys be taken during the program. The corporate committee also requested that four observational surveys be taken during the program. In this paper, the results of the program developed at Ford's Research and Engineering Center will be presented. The Research and Engineering Center employs about 14,000 people working in some 30 buildings scattered in an area just outside Detroit, Michigan. Formation of a local committee for such a large complex of buildings presented several interesting problems which will be discussed. Once the main committee was in place, three subcommittees–awareness, incentives, and surveys–were formed to guide the important aspects of the program. The awareness subcommittee had to develop a training program and then find and train volunteers to run the awareness sessions. The incentives subcommittee had to plan and secure an incentives budget and then find a way to distribute the incentives. The survey subcommittee had to plan, conduct, analyze and report results of the surveys. Also, approximately 75 observers had to be trained in order to cover the 42 different entrances and the three different work shifts. For the midnight and the day shifts, observations of shoulder belt usage for both driver and right front passenger were made as vehicles entered the workplace. For most of the buildings that had afternoon shifts, the same observations were made as vehicles exited the workplace. Tape recorders were used to record the observations at entrances having a high traffic volume and at the main entrance used by the midnight shift. About every 5–10 minutes observers also noted the time of day so that a distribution of arrival times could be determined for each entrance. Approximately 12,000 observations were made on each of the four surveys. A baseline survey taken in late April prior to the start of the program showed a wearing rate of 38.7%. A survey in early June immediately following the completion of all awareness sessions showed the overall usage rate had increased by 15 percentage points to 53.7%. A third survey taken in mid-September near the need of the program indicated that during the incentive phase, the employee belt usage had increased another 9 percentage points to 63.1%. The final survey, on October 31, showed that usage rate was holding at 63% even though the program had been completed at least one month earlier in most buildings. During the next several months there were no organized safety belt activities. In April of 1985, prior to the start of the 1985 employee safety belt campaign, another survey was taken. Belt usage dropped only slightly to 59.5%. We were extremely pleased with such a high response maintenance. Over 2,500 more employees have now made belt wearing a part of their normal driving behavior. Although the Research and Engineering Center has primarily a salaried workforce, similar programs developed at other Ford facilities showed comparable gains in employee belt usage. Based on testimonials we have received, we know that a number of lives have been saved and injuries reduced as a result of this program.

Noncrash Motor Vehicle Accidents

Injuries caused by hitting against the vehicle interior during a noncrash motor vehicle accident are noteworthy. Data on children 0 to 15 years of age involved in motor vehicle accidents were obtained from an ongoing multihospital monitoring system. Approximately 12% of the passengers were injured in a noncrash accident. One half of the noncrash injuries were caused by a child hitting against the vehicle interior during a sudden stop, turn, or swerve or after losing balance in a moving vehicle. Most of these accidents involved a child between 1 and 4 years of age who was traveling in the front passenger seat unrestrained. While most of the injuries were minor, some children sustained serious injuries. An analysis of the cases indicated that most of these injuries could have been avoided if the child had been restrained. Medical costs as well as use of medical resources could have been saved by preventing these noncrash injuries.

Analysis of passenger vehicle accident damage

The results of a three month study, involving the use of traffic law enforcement officers to record detailed information on vehicle damage at the scenes of motor vehicle accidents, is presented. The data collected throughout the study was recorded on specially designed questionnaire forms. These provided additional information not normally noted by the accident reporting authorities. The study resulted in damage data being recorded for a total of 406 passenger vehicles. This accounted for only 20% of the actual number of accidents occurring throughout the survey period in the region covered by the study. However, as has been shown elsewhere (Tedford and Milne 1981), the data accurately reflected the true accident pattern and thus provided an acceptable basis for statistical analysis. The results were analyzed with respect to the possible effects vehicle damage might have on the positioning and orientation of child safety seats within the passenger compartment. It was found that the risk to a restrained child in the front passenger seat from broken glass, as a result of a shattered windshield, was relatively small. The risk of injury from large loose objects being transported inside the vehicle was also small. However, the problems of vehicle encroachment and the rigidity of vehicle seats, following impact, suggested the front passenger seat to be a high risk zone, when compared to the center back seat position.

Nitrosamines in new motor-cars

Volatile nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), N-nitrosodiethylamine (NDEA) and possibly N-nitrosodibutylamine (NDBA), have been found as airborne contaminants inside new (1979 model) motor-cars. NDMA was found in the front passenger area of 37 of the 38 motor-cars at levels ranging from 0·07 to 0·83 μg/m 3 (mean 0·29 μg/m 3), NMOR was present at levels between a trace and 2·5 μg/m 3 (mean 0·65 μg/m 3) in 16 vehicles and 0·04–0·39 μg NDEA/m 3 (mean 0·11 μg/m 3) was detected in 17 of the cars. Traces of NDBA (<0·01 μg/m 3) were also tentatively identified in three of the vehicles. The exposure of man to volatile N-nitrosamines from motor-cars is estimated to be similar to that from bacon and beer.