TRAFFIC FATALITIES It's the first snow of winter that sneaks up on drivers

The fatality rate increases during the first snow of the season, an expert notes.
SCRIPPS HOWARD
Drivers, especially elderly drivers, seem to forget from winter to winter about the dangers of driving in snow, and pay the price each season when the first flakes fall.
A new study of more than 1.4 million fatal crashes over 25 years found that even though fewer fatal accidents occur on snowy days overall than on dry days, the first snowy day of the season was substantially more dangerous than others in terms of deadly crashes, especially among seniors.
The research, published today in the January issue of the American Journal of Public Health, continues work linking traffic fatalities and injuries to various weather conditions that was started by researcher Daniel Eisenberg when he was at the University of California-Berkeley. He's now at the University of Michigan.
Last year, he published results showing that the more it rained or snowed in a particular month, the fewer deadly traffic accidents there were. But he also noted that the risk of crashes and fatalities rose on the first day of precipitation after a dry spell, and that accidents spiked higher for each day since the last rain or snow.
Eisenberg attributes the jump to two things: oil and debris accumulating on roads when there is no precipitation to wash it off and because "people aren't as used to driving in the rain when it comes after a long dry spell. Perhaps they become better adapted to the weather conditions by day two or three," he said.
Novelty of it
For snow driving, which Eisenberg estimates averages 18 days a year in most of the lower 48 states, the novelty of the first snow is even greater, and may catch more drivers off guard.
"The first snow of the season significantly increases the fatality rate," Eisenberg said, noting that some recent reports by weather and traffic experts have suggested that extra effort be made to warn motorists of the risks on such "first" days.
On the other hand, since more people tend to stay off snow-covered roads and typically drive more slowly and cautiously in snow, there is an overall reduction in the number of fatal crashes on snowy days, Eisenberg and Michigan colleague Kenneth Warner found.
But the reduced visibility and poorer traction of snow driving cause more nonfatal crashes with injuries, the researchers found. "Compared with dry days, snow days result in a reduction of the most serious crash outcome, fatalities, but an increase in less serious outcomes," Eisenberg said.
The researchers matched fatal wrecks with daily state weather reports compiled by the National Climatic Data Center from 1975 through 2000. They also compared an additional 26 million nonfatal accidents in 17 states during the 1990s with weather data.
"The greatly increased fatality rate for the elderly during first snowfalls is especially troubling," the researchers wrote. "Either they do not reduce their driving as much during first snowfalls as during subsequent snows, or they do not adjust their driving behavior in response to the beginning of the snow season as quickly as do the nonelderly."