TUESDAY, April 10, 2012 (HealthDay News) -- The upcoming income tax filing deadline might be taxing in more ways than one for Americans: A new study suggests that fatal crashes jump on Tax Day, possibly as a result of last-minute filers carelessly rushing to the post office to mail their returns.
The study's lead author said the research indicates that "stressful deadlines lead to driver distraction and human error."
"Almost all of these crashes could have been totally avoided by a small change in driver behavior. An awareness of this risk could lead to better road safety," said Dr. Donald A. Redelmeier, a professor of medicine at the University of Toronto.
But others who study traffic said it's hard to understand what the findings mean since other possibilities, such as more cars on the road, rather than lots of people too revved up to pay attention, could drive up crash statistics on Uncle Sam's big pay day.
"The problem with announcing that any one day has a greater-than-normal number of traffic crashes is that often, when adjusted for the higher number of travelers, the crash rate isn't actually higher than a typical weekend day," said Tom Vanderbilt, author of the book "Traffic: Why We Drive the Way We Do (and What It Says About Us)."
For the new study, published in the April 11 issue of the Journal of the American Medical Association, Redelmeier and a colleague examined a database of fatal U.S. traffic accidents from 1980 to 2009. They looked specifically at crashes on the date taxes were due and the same day the week before and the week after.
While the federal government's typical filing deadline is April 15, it falls on Tuesday, April 17, this year.
Although the risk of dying on Tax Day is extremely small, it's a bit higher than on the other days. The researchers found an average of 226 fatal accidents on annual tax-due days compared to 213 on the other days. The increased risk is about 6 percent.
Increased risk was greatest for people younger than 65, the researchers said.
Redelmeier, who has investigated traffic fatality rates on other special days, said Tax Day is about as risky on the roads as Super Bowl Sunday. In 2008, he also reported that fatal crashes are more likely during polling hours on presidential election days, compared to other Tuesdays around the same time.
He said he thinks stress is the accelerator here. "It doesn't just hold on Tax Day but might also hold to other distinctly stressful times, such as when you're going through a divorce or something is wrong with your child or you've just lost your job," he said.
Chandra Bhat, a professor of transportation engineering at University of Texas at Austin, raised questions about the study. For one thing, he said, the study finds that people under the age of 18 are involved in more fatal crashes on Tax Day. It's not clear if they're passengers or drivers, he said, adding that if they're drivers, it's unlikely the crash increase is related to the tax deadline.
"Traffic accidents are such relatively rare events that a one-day period of observation may be inadequate to make conclusive observations," Bhat cautioned. "While I appreciate that the analysis design followed by the authors is quite good and that the authors have considered several years in their analysis, I still would be somewhat cautious in drawing conclusions."
Since the study didn't account for factors such as sleep deprivation, the authors recommend additional research that would ultimately beef up efforts aimed at prevention.
For now, they said, drivers should be reminded to wear seat belts, drive the posted speed limit and avoid alcohol on April 17.
For more about traffic safety, see the U.S. National Library of Medicine.