A.James McKnight

THE EFFECT OF CELLULAR PHONE USE UPON DRIVER ATTENTION

In this study, 150 subjects observed a 25-minute video driving sequence containing 45 highway traffic situations to which they were expected to respond by manipulation of simulated vehicle controls. Each situation occurred under five conditions of distraction: placing a cellular phone call, carrying on a causal cellular phone conversation, carrying on an intense cellular phone conversation, tuning a radio, and no distraction. All of the distractions led to significant increases in the proportion of situations to which subjects failed to respond. However, significant age differences of nonresponse appeared. Among subjects over age 50, nonresponses increased by about one-third under all of the telephone distractions. The response rate of younger subjects increased by a lesser degree except under intense conversation. Results were not influenced by gender or prior experience with cellular phones. The authors conclude that older drivers might reduce their accident risk during attention-demanding traffic conditions by avoiding use of cellular phones and that other drivers might do so by refraining from calls involving intense conversation.

MULTIVARIATE ANALYSIS OF AGE-RELATED DRIVER ABILITY AND PERFORMANCE DEFICITS

A computerized measure of 22 visual, attentional, perceptual, cognitive and psychomotor abilities and a structured road test were administered to 407 elderly drivers age 62 and above. Approximately two-thirds of the sample had been referred to licensing agencies on the basis of observed unsafe incidents and the remainder were volunteers free of reported incidents. Significant correlations (r = 0.4-0.5) were found between unsafe driving incidents and deficiencies in attentional, perceptual, cognitive and psychomotor categories and 0.3 for the visual. A total score based upon all ability measures correctly identified 80% of incident-involved, while misidentifying only 20% of the incident-free drivers. Unsafe driving incidents evidenced significant but small positive correlations (r = 0.1-0.2) with road test errors indicative of skill deficiencies but not with errors in routine safe driving practices. Substantial examiner differences attenuated relationships involving road performances, and correlations with skill-related performances rose (r = 0.2-0.3) when these effects were partialled out. Intercorrelations among measured abilities were high, indicating the need for caution in interpreting reported relationships between individual abilities and unsafe driving incidents. The authors also caution against interpreting correlations found in highly selected samples as representing the magnitude of relationships in the population at large.

EVALUATION OF PEER INTERVENTION TRAINING FOR HIGH SCHOOL ALCOHOL SAFETY EDUCATION

A program of peer intervention in the drinking and driving of others compared with a conventional alcohol safety program in the high school setting. The peer intervention program led to significant increases in self-reported intervention behavior following completion of the course. The conventional alcohol safety program failed to produce changes in intervention behavior during this period. Both the peer intervention program and the conventional alcohol safety program led to significant knowledge gains. Neither program led to significant measured shifts in attitudes.

THE EFFECTS OF MOTORCYCLE HELMETS UPON SEEING AND HEARING

This study assessed the effects of motorcycle helmets upon seeing and hearing by having 50 riders operate over a test route, changing lanes in response to an audible signal under three helmet conditions: none, partial coverage, and full coverage. Half of the subjects were assessed for the degree of head rotation during the lane changes, while the other half were assessed for hearing threshold (decibel level at which they first responded to the signal). Results showed that subjects in the vision study increased the degree of head rotation in proportion to the vision restriction imposed by the helmets, though not to the full extent of the restriction. However, individual differences in head rotation far exceeded the effect of variation in helmets. Subjects in the hearing study evidenced no differences in hearing threshold across the three helmet conditions. The authors conclude that the effects of helmets upon the ability to see and hear are, at most, far too small to compromise the safety benefits offered by head protection.

Accident prevention versus recidivism prevention courses for repeat traffic offenders

Most U.S. jurisdictions include some form of educational program among the driver improvement actions for repeated traffic offenders. The majority of programs fall into two categories: accident prevention programs seeking primarily to foster safe driving practices, and recidivism prevention programs seeking primarily to foster lawful driving behavior. Over 16,000 multiple traffic offenders were divided between courses representing each type of program. Those taking part in the recidivism prevention course evidence significantly fewer accidents and violations during the following year than did their counterparts participating in the accident prevention course. Offenders failing to participate in either course, and therefore having their licenses suspended, showed significantly fewer accidents and violations than did participants in either course. The results suggest that instruction designed primarily to reduce recidivism is more effective in reducing both violations and accidents of repeat offenders than instruction that is solely directed toward accident prevention.

Development of a standardized boating sobriety test

A sobriety test capable of being administered on boats was developed as an aid in establishing probable cause to request a breath sample of recreational boat operators suspected of being over the legal alcohol limit. In a laboratory phase some 12 candidate measures suitable for use in a boating environment were assessed for their relationship to blood alcohol levels through administration to 32 subjects tested at blood alcohol concentrations (BACs) of 0.00, 0.06 and 0.12%. Four measures showing significant relationships to BAC were then administered by marine police to a sample of 60 recreational boaters found to have BACs ranging from 0.0 to 0.20%. Three measures still showing significant relationships to alcohol were horizontal gaze Nystagmus given in a seated position, reciting the alphabet from A to Z, and clapping hands alternately with palm and back of hand, while counting. Correlation of the measures with BAC, and the ability to distinguish boaters over and under a 0.10% limit were similar to those found over the same BAC range with the standardized field sobriety test (SFST) for motor vehicle operators. Where there is not sufficient cause to request a boat operator to proceed to shore for testing, a standardized boating sobriety test (SBST) making use of the three measures appears to be a suitable replacement for the SFST.

The Automated Psychophysical Test (APT) for assessing age-diminished capabilities

In this report we describe a computer-based psychophysical test that can assess capabilities that have been shown through research to be related to both age and automobile accidents. The test operates with a standard personal computer. To facilitate its use with an elderly population, instructions are given aurally by means of a sound card as the exercises are demonstrated. Responses are registered with a joystick; the direction of the joystick’s motion corresponds to the direction or location of stimuli on the screen to obviate the learning of response codes. The sys-tem is currently being used to study the diminished capabilities of elderly drivers who have been referred to a state licensing agency because of deficient driving behavior.

AN EXPERIMENTAL EVALUATION OF DRIVER LICENSE MANUALS AND WRITTEN TESTS

Written manuals and tests dealing with safe driving practices were designed for licence applicants in three categories: New Drivers, Renewals and Older Drivers. Contents were based upon an analysis of the critical information requirements of each group. The manuals and tests were evaluated in an experiment involving over 30,000 license applicants. Among New Drivers, the treatment group had significantly fewer accidents than a control group administered the regular drivers manual. Among Renewals, the treatment group had significantly fewer accidents with convictions than a control group not required to take a test. No consistent effects were found for Older Drivers. It was concluded that well-designed manuals and tests are a cost-effective accident countermeasure.