A 100-car naturalistic driving study conducted by the Virginia Tech Transportation Institute has shown that fatigue is a cause of a higher percentage of crashes than previously estimated. And 18- to 20-year-olds account for significantly more fatigue-related crashes than any other age group.
One-hundred drivers who commuted into or out of the Northern Virginia/Washington, DC, metropolitan area were initially recruited as primary drivers to have their vehicles instrumented or to receive a leased vehicle instrumented for the study. Since other family members and friends would occasionally drive the instrumented vehicles, data were collected on 132 additional drivers.
Researchers selected a larger sample of drivers below the age of 25, compared with the total population of drivers, and a sample that drove more than the average number of miles.
The data acquisition system used for the 100-Car Study was developed by engineers at the Virginia Tech Transportation Institute. Sensors included five video channels, forward and rearward Vorad radar units, accelerometers, lane-tracking software, and an in-vehicle network sensor. The cameras were mounted unobtrusively in order to facilitate naturalistic driving behavior.
Researchers viewed more than 110,000 events in order to validate 10,548 events, specifically, 82 crashes, including 13 where the data were incomplete; 761 near crashes; 8,295 incidents, such as braking hard for slowing or stopped traffic; and 1,423 non-conflict events, such as running a stop light with no traffic present.
In addition, 20,000 randomly selected 6-second segments of video were viewed. Incidents of moderate to severe driver fatigue were noted, providing an estimate of the amount of time drivers were fatigued but were not involved in a crash or near-crash.
The total number of subjects who were involved in fatigue-related crashes and near-crashes was 38, with 11 drivers accounting for 58% of all the fatigue-related crashes and near-crashes.
“Applying the findings to the population at-large, these results suggest that drivers are at a four times greater risk of a crash or near-crash if they choose to drive while fatigued,” said Tom Dingus, director of the Virginia Tech Transportation Institute. “That suggests that about 12% of all crashes and near-crashes in the population are attributable to fatigue.”