Staying active often means continuing to drive, although maybe not as much. New analyses are refining our understanding of the risks involved when older people drive.
Despite public concerns about older drivers, research has indicated that, as far as fatality risks are concerned, older motorists are a danger mainly to themselves. Now a new Institute analysis looking at both fatal and nonfatal injury rates does show a modest increase in the risk of nonfatal injuries to occupants of other vehicles involved in collisions with vehicles driven by older people, compared with drivers 30-59 years old.
The largest increase in the risk for occupants of the other vehicles was observed among the oldest group of drivers (those 85 and older). This finding, which is based on insurance injury liability claims results, suggests that as drivers get older they become increasingly likely to be at fault in their collisions.
The new study examined injury rates using three federal data sources — the Fatality Analysis Reporting System, National Automotive Sampling System/General Estimates System, and Nationwide Personal Transportation Survey. The study also examined insurance data from the Highway Loss Data Institute. The researchers analyzed fatal and nonfatal injury rates for four groups of people, including drivers, their passengers, occupants of other vehicles, and others on the road (pedestrians, motorcyclists, and bicyclists).
"The main strength of this study compared with previous ones we've conducted is the variety and scope of the data sources we used this time around. We looked at the potential hazards associated with older drivers from a number of vantages," says Susan Ferguson, Institute senior vice president for research. Death rates for drivers 70 and older and for their passengers, who also were likely to be older people, were higher than for 30-59-year-old drivers and their passengers. However, the older drivers weren't more likely to be in collisions that were fatal to other vehicle occupants or to other people on the road. Nor were drivers 70 and older more likely than 30-59 year-olds to be in collisions resulting in nonfatal injuries to pedestrians, motorcyclists, and bicyclists.
Deaths per 100,000 drivers, by driver age, 1993-97
Death rates for drivers 70 and older and for their passengers are higher than for 30-59-year-old drivers. However, the risk of death isn't higher for occupants of the other vehicles involved in crashes with older drivers. Nor is the risk higher among pedestrians, motorcyclists, and bicyclists.
Claims per 1,000 insured vehicle years, by driver age and type of claim, model years 1999-2001
Insurance claims for injuries to others and damage to their property go up for older drivers, which indicates they more often are deemed to be at fault in their collisions. The property damage liability claim rate starts going up at age 70 and is highest among drivers 85 and older.
This confirms the findings of earlier research that older drivers themselves suffer the most severe consequences of their crashes (see Status Report special issue: older drivers, Sept. 8, 2001). Still, some older drivers do pose an increased risk of nonfatal injury to other people on the road. The new Institute study indicates that drivers 75 and older are about 10 percent more likely than 30-59 year olds to be involved in two-vehicle collisions in which the occupants of the other vehicles suffer nonfatal injuries.
Analysis of insurance claims data reinforces this finding, indicating an increase in older driver liability for the injuries in their crashes (liability claims are paid when an insured driver is deemed at fault in a collision). Among older people, the property damage liability claims rate starts climbing at age 70 and is highest among drivers who are 85 and older. The claims rate for drivers in this age group approaches the rate for teenagers.
Compared with drivers ages 30-59, those 75 and older show increasingly higher bodily injury liability claims rates. By age 85 and older, these rates are about 80 percent higher than for 30-59 year-olds. However, the bodily injury liability claims rate for the oldest drivers still isn't as high as it is for teenage drivers.
"These findings suggest that the oldest drivers are overinvolved in crashes, but they're less likely than teenage drivers to hurt other people. The beginning drivers still are the ones we have to worry about the most," Ferguson points out.
Elisa Braver, senior epidemiologist at the Institute, adds that "drivers younger than 30 are responsible for far more injuries and lives lost than senior drivers. When people do die in crashes in which older drivers are involved, it's usually the older people themselves and their passengers who suffer. Much of their increased risk comes from increased susceptibility to injury."
Continuing efforts to improve occupant protection "will benefit both older and younger drivers and passengers," Braver adds. "Research on developing valid and feasible driver screening tests should continue, too. This could help older drivers, their families, and physicians decide whether and when to modify driving habits."