Fall driving more hazardous than summer or winter

July 14, 2009

(PhysOrg.com) -- While many believe summer is the most dangerous season on U.S. roads because motorists tend to drive faster, drink more alcohol and drive more often for leisure, a new report by the University of Michigan suggests otherwise.

Fatality crash rates are highest in the fall, with October at the top of the list (10.2 deaths per billion kilometers), according to a study in the current issue of the journal Traffic Injury Prevention.

Using the fatality data and distance-driven data from the Department of Transportation, Michael Sivak of the U-M Transportation Research Institute calculated the fatality rate and per distance driven for each month from 1994 to 2006.

He found that October, November and December have the highest fatality rates and March the lowest (8.8 deaths per billion kilometers), followed by February and April. From March to October, rates increase each month and then decline from October to March, despite the weather.

"The risk of a fatality per distance driven in October is about 16 percent greater than the risk in March," Sivak said. "Everything else being equal, inclement weather—snow and ice—-should increase the risk of driving. However, because inclement also leads to general reductions in speed, the net effect is not clear."

Likewise, there are several factors more prevalent during summer that would suggest that the driving risk should be greater during those months, Sivak says.

"For example, leisure driving, which occurs more frequently on unfamiliar roads, at higher speeds, at night and under the influence of alcohol, is riskier than commuter driving," he said. "Although hard data are not available, leisure driving is likely to be most frequent during summer months when school is out. In addition, consumption of beer shows a strong seasonal variation, peaking in summer months."

So why are October, November and December more dangerous for motorists than other months of the year? One possible reason could be the duration of darkness, which increases in the fall and is longest in late December. But Sivak says there is no single cause.

"There are several known factors with major influences on the risk of driving that show strong seasonal variations," he said. "However, the peaks and troughs of the seasonal variations of these factors do not fully match the pattern of the overall risk. Thus, the driving-risk pattern is likely a consequence of joint contributions of several factors."

Provided by University of Michigan (news : web)

Explore further: More pedestrians killed during a new moon

Related Stories

Teen drivers would benefit from greater restrictions

January 14, 2008

Most states have graduated licensing for teen drivers but such programs should be even more restrictive, according to a study by the University of Michigan Transportation Research Institute.

Driving while phoning danger as bad as drink-driving

June 12, 2008

Motorists who use cellphones while driving make as many, if not more, driving errors as clinically drunk drivers, according to educational psychologist Professor Michael Townsend. He says the proposed ban on hand-held cellphone ...

Major drop in traffic deaths: It's more than high gas prices

July 28, 2008

(PhysOrg.com) -- Rising fuel prices, resulting in less driving, may very well be a reason for the decline in traffic deaths, as recent reports have suggested. But a new report by the University of Michigan shows that something ...

Declining road fatalities: Less driving not the only cause

June 4, 2009

(PhysOrg.com) -- Fewer Americans are dying on our nation's roads, not only because they are driving less, but also because the type of driving has changed, says a researcher at the University of Michigan Transportation Research ...

Recommended for you

Chimpanzees shed light on origins of human walking

October 6, 2015

A research team led by Stony Brook University investigating human and chimpanzee locomotion have uncovered unexpected similarities in the way the two species use their upper body during two-legged walking. The results, reported ...

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...

The hand and foot of Homo naledi

October 6, 2015

The second set of papers related to the remarkable discovery of Homo naledi, a new species of human relative, have been published in scientific journal, Nature Communications, on Tuesday, 6 October 2015.

How much for that Nobel prize in the window?

October 3, 2015

No need to make peace in the Middle East, resolve one of science's great mysteries or pen a masterpiece: the easiest way to get yourself a Nobel prize may be to buy one.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jul 14, 2009
Wet leaves on the pavement.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.