The Hazards of the Winter Roads

January 4, 2012 · 0 comments

We all know winter is a tough time for drivers, not only with wet and icy roads but also with poor visibility due to more dark hours, low sun angles, valley fogs, or blowing snow.
Right there you have two different problems: adverse road conditions, and adverse atmospheric conditions.
Which hazard is more of a seasonal phenomenon, and which is the greater risk to drivers? And given regional variations in winter conditions, how do the risks change with your location and time of year? Do risks depend on whether you’re driving a big or small vehicle?
Recently, Allan Curtis of the University of Lincoln and his colleagues have been putting a quantitative edge to such questions by analyzing more than 100,000 fatal crashes, one-fifth of them with commercial trucking. Some results so far that they’ll present Wednesday, 25 January (10:30 a.m., Room 348/49) at the AMS Meeting in New Orleans include:
  • 17% of all fatal accidents and 7,130 persons are killed in weather-related accidents each year.
  • The Midwest has the greatest average intra-annual variability for both trucks and passenger vehicles. For large commercial trucks, the average monthly peak occurs in January with 38.29% of accidents occurring with adverse-weather, and a minimum in June of 8.27%. For passenger vehicles, accidents are less affected by adverse-weather with an average intra-annual peak of 30.28% in January and a minimum of 6.32% in June.
  • The South has the least average intra-annual variability of accidents in adverse-weather.
  • Adverse-road related accidents are greater in all regions than adverse-weather due to the fact that accidents can occur on wet or snow/ice covered roads in the absence of adverse-weather.
One can imagine taking Curtis et al.’s data and parsing out when the forecasts for road conditions are likely to be more meaningful to drivers than forecasts for the weather itself, among other applications. Stay tuned for the presentation in a few weeks.