The stretches of Treasure Valley roads most likely to prompt a snow-, ice- or slush-related crash are on Interstate 84. And the top two are within a mile of each other, between the Cole Road overpass and the Flying Wye.

When wintry conditions are removed as contributing factors, I-84 doesn’t even crack the top 15 most accident-prone places, according to data from the Idaho Transportation Department.

Idaho State Police Capt. Steve Richardson said the discrepancy arises because freeway drivers, especially in the area of the Flying Wye, are handling a complex array of decisions — lane changes, interchanges and traffic leaving and entering the freeway — all while driving at high speed.

In good conditions, when roads have what Richardson described as a higher “coefficient of friction,” that’s usually not a problem.

“What you could get away with on dry pavement, probably pretty handily in some circumstances, you could be done for when it’s a lower of coefficient of friction or slipperier surface,” Richardson said. “An overreaction on a dry road, you swerve a little bit but you’re still in your lane. But if it’s icy or snowy, that may mean you’re in the next one or two lanes and (have) a much greater chance of hitting another car, the guardrail, whatever the case may be.”

Another aspect of freeway driving that leads to a disproportionate number of winter crashes is the likelihood of bridges, Richardson said. Air under bridge decks cools faster than the ground, allowing ice to form even when the roads leading to and from the bridges remain thawed.

Whether they’re on the interstate or surface streets, drivers need to adjust for conditions, law enforcement officers across the Treasure Valley said. That means slowing down, leaving more distance between cars and using the accelerator and brake pedals cautiously.

“The problem is driving behavior doesn’t change when there’s snow,” Boise police spokeswoman Lynn Hightower said.

The consequences of driving in winter with the same approach as in summer are particularly noticeable on the three Meridian Road intersections south of I-84. Its intersections with Amity, Victory and Overland roads rank, respectively, as the Valley’s 19th, 17th and 23rd most likely for crashes related to slick conditions.

Northbound drivers going toward the interstate are a big part of the problem, said John Gonzales, a traffic sergeant for the Meridian Police Department. The speed limit on Meridian is reduced from 55 mph to 45 as the road approaches the freeway, but maybe not dramatically enough, Gonzales said.

He suggested a lower speed limit may be appropriate between Rosalyn Court and Calderwood Street because of the rapid increase in traffic density. He said he’d like the state to conduct a traffic study to determine just how low the speed limit should be on that stretch.

Winter crashes appear no more likely to claim lives than those that occur the rest of the year. On the 24 sections of Treasure Valley roads where motorists were most likely to crash in ice, snow or slush, not a single fatal accident occurred because of those conditions, according to statistics.

“While there tend to be more crashes in the winter, they tend to be less severe because people slow down and drive more cautiously in bad weather/road conditions,” Idaho Transportation Department spokesman Reed Hollinshead said.

Sven Berg: 377-6275