When rain starts falling after a dry period, it mixes with dirt, dust and oil on roadways, and the result can be roads that are almost as slick as ice.
When that happens in the fall -- as it has here this week -- fallen leaves on streets can worsen the situation. And they have.
It is on days with conditions like those of Wednesday and Thursday that police brace for an increased number of traffic accidents.
"In the first hour or so, we're saying, 'Get the accident reports and get ready,'" said one policeman. "It usually hits like the full moon."
In a 36-hour period that began Wednesday morning, Cape Girardeau police responded to 22 vehicle accidents, 15 of which could be partially blamed on the weather. Even so, the numbers weren't significant; it was typical of any rainy day.
Jackson and Scott City police actually reported fewer traffic accidents during the period, much to their delight and surprise. Jackson reported four accidents; Scott City just one.
Still, even with average numbers or numbers lower than usual, police know that there is always the potential for more traffic accidents on rainy days.
Rear-end smashes are common on rainy days because vehicles take longer to stop on wet pavement.
"One of the first statements we often hear (on rainy days) is that the driver tried to stop but couldn't and slid into the other car," said Cpl. David Sanders of the Cape Girardeau police traffic division.
Several of the accidents in Cape Girardeau were rear-end accidents.
In one accident, the problem wasn't that the car wouldn't stop, but that the wet pavement made it difficult for the car to move forward. The driver of one car turned in front of another vehicle. When the driver noticed the other vehicle, she tried to accelerate, but found her tires spinning on the wet pavement. She was issued a summons for failing to yield.
"From a safety perspective, motorists need to be aware of the road conditions," said Cape Girardeau police Sgt. Carl Kinnison.
"But people are in a hurry and often forget that the streets are slick."
An accumulation of leaves on roadways don't present a significant problem, but when a motorcyclist turns a corner and hits a patch of wet autumn leaves, there is an increased danger of falling, Kinnison said.
Kinnison said driving with poor road conditions can be made safer if motorists would remember and follow a few recommendations.
First, slow down. "People forget that speed limits are based on ideal road conditions," Kinnison said.
"A good rule of thumb is to reduce your speed by 5-to-10 miles per hour when the roads are wet. On the interstate, go no more than 60," he said.
A second recommendation is to not follow so closely, a major problem in Cape Girardeau, said Sanders. In any weather, the closer a driver follows, the more difficult it is to stop.
Kinnison and Sanders agreed that a driver should be conscious of the road conditions and the effect of the weather on driving.
Sanders also reminded motorists that the condition of the roads is no excuse in an accident; a driver may be issued a summons in an accident even if road conditions are poor.
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