What’s the Riskiest Month to Drive in the U.S.?

The answer, interestingly, is October. That’s what Michael Sivak concludes in a new paper in Traffic Injury Prevention.

March has the lowest fatality rate (8.8 per billion kilometers), followed by February and April. Thus, the risk of a fatality per distance driven in October is about 16 percent greater than the risk in March.

Sivak notes that the factors for seasonal variation in crash risk are, as one might expect, complex — ranging across everything from alcohol consumption to “duration of darkness” to leisure driving (“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”) to weather (“Inclement weather (e.g., snow and ice), everything else being equal, should increase the risk of driving. However, because
inclement weather also leads to general reductions in speed, the net effect is not clear.”)

In light of all these, October seems a bit strange; not as much vacation driving as during the summer, inclement weather hasn’t kicked in in most places, though the onset of earlier darkness might be an issue (not to mention the outlier day of Halloween).

This entry was posted on Tuesday, July 14th, 2009 at 12:18 pm and is filed under Risk, Traffic safety. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

3 Responses to “What’s the Riskiest Month to Drive in the U.S.?”

  1. Elaine Says:

    Until the last year (or two?) Daylight Savings Time has ended in October, which can lead to some fairly radical changes in when it gets dark/light. I have no idea if that has any effect, but it certainly seems like it could.

    Also, inclement weather starts to kick in about mid-October, at least in this area (Pac NW), and it’s enough of a shift from summer and early fall that folks are still readjusting. I seem to remember a similar “first rain makes people drive like idiots” effect growing up in southern California, too.

  2. Vin Says:

    Based on the weather/leisure-driving equation, my guess would’ve been December (bad weather, lots of people taking holidays and going to parties that involve drinking, general increase in traffic and stress due to holiday shopping). But this might be one of those things where the differences are small enough to be insignificant.

    Elaine: interesting point about the weather in October, though it’s worth noting that in most of the U.S. it rains pretty evenly throughout the year.

  3. Botswana Meat Commission FC Says:

    Could October also be more dangerous because it’s a big month for college football? Lots of intoxicated drivers, and being most popular in the south and midwest, lots of driving to/from on rural roads. NFL is also in full swing and I believe Nascar has races in Oct. too.

    just a theory!

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