Using cognitive status to predict crash risk: blazing new trails?

Introduction: A computer-based version of an established neuropsychological paper-and-pencil assessment tool, the Trail-Making Test, was applied with approximately 700 drivers aged 70 years and older in offices of the Maryland Motor Vehicle Administration.

Method: This was a volunteer sample that received a small compensation for study participation, with an assurance that their license status would not be affected by the results. Analyses revealed that the study sample was representative of Maryland older drivers with respect to age and indices of prior driving safety.

The Maze Test: A significant predictor of older driver crash risk.

A study sponsored by the National Highway Traffic Safety Administration performed functional assessments on approximately 700 drivers age 70 and older who presented for license renewal in urban, suburban, and rural offices of the Maryland Motor Vehicle Administration. This volunteer sample received a small compensation for study participation, with an assurance that their license status would not be affected by the results. A comparison with all older drivers who visited the same sites on the same days indicated that the study sample was representative of Maryland older drivers with respect to age and prior driving safety indices.

'Low mileage bias' and related policy implications--a cautionary note.

This research examined a relationship asserted in recent literature in the field of traffic safety and injury prevention--that a significant indicator for elevated crash risk among older drivers, and potential trigger for individualized assessment at license renewal, is a low (<3000 km) annual driving distance. Sampling problems in earlier reports, in particular a reliance on self-report measures of both exposure and crash involvement, are highlighted. A pattern of misestimation for those who self-report an extremely low or extremely high number of miles driven is documented, that casts serious doubt upon the effect reported earlier.

Job change rate as a crash predictor for interstate truck drivers.

This research analyzed the Motor Carrier Management Information System (MCMIS) database to develop estimates of the increased risk of crash involvement experienced by commercial drivers who change jobs frequently. These analyses quantified the risk of single- and multiple-crash involvement as a function of annual job change rate, and expressed the relative risk for drivers with more versus fewer job changes through calculation of the "odds ratio" statistic. Significant odds ratio values were found, indicating that crash risk begins to rise when a driver has averaged more than two jobs with different employers each year for 2 years or longer, and that the odds of being involved in multiple crashes more than doubles for drivers with three or more jobs per year during this same interval.

Driver's exposure to distractions in their natural driving environment.

Unobtrusive video camera units were installed in the vehicles of 70 volunteer drivers over 1-week time periods to study drivers' exposure to distractions. The video data were coded based on a detailed taxonomy of driver distractions along with important contextual variables and driving performance measures. Results show distractions to be a common component of everyday driving.

MaryPODS revisited: updated crash analysis and implications for screening program implementation.

Problem: Due to the relative scarcity of crashes, there has consistently been a problem with analyses that use crashes as a criterion measure in their analyses.

Method: Previous analyses of the relationships between functional capacity measures and at-fault crash involvement for older drivers as reported in the NHTSA Model Driver Screening and Evaluation Program Final Technical Report have been updated to include one additional year of driving experience. Eighteen new at-fault crashes involving drivers who previously had no crash involvement were recorded for the Maryland Motor Vehicle Administration (MVA) test sample during this interval.

The causes and consequences of distraction in everyday driving.

To document drivers' exposure to potential distractions and the effects of these distractions on driving performance, inconspicuous video camera units were mounted in the vehicles of 70 volunteer subjects. The camera units automatically recorded a closeup view of the driver's face, a broader view of the interior of the vehicle, and the roadway immediately ahead of the vehicle whenever it was powered on. Three hours of randomly selected data per subject were coded based on a taxonomy of driver distractions (talking on cell phone, eating, tuning radio, etc.