Bridges and overpasses are the most dangerous parts of the road in the winter. They are the first to freeze and the last to thaw because they’re built of concrete, which doesn’t retain as much heat as other materials. Be safe while driving on icy roads by remembering the following:
- Turn off your cruise control, be alert and drive cautiously.
- Roads that are wet or have fresh snow, packed snow, or ice have varying degrees of traction. Adjust your speed to match road conditions accordingly.
- Increase your distance from vehicles in front of you. Allow about three times as much space as usual.
- If your vehicle suddenly feels like it’s floating, gradually slow down. Tap on your brakes gently; don’t slam on them.
- Changes in elevation can drastically affect road and weather conditions. Watch for icy spots, especially in shaded corners.
- Avoid driving through snowdrifts — they may cause your vehicle to spin out of control.
- Blowing powder or dry snow can limit your visibility, especially when approaching or following trucks or snowplows. Keep your distance to avoid being blinded by blowing snow.
- Look for signs of ice on windshield wipers, side view mirrors, road signs, trees or fences. If ice has formed on any of these things, it may be on the road as well.
Invisible Danger: Black Ice
Black ice, also called glare ice or clear ice, is a thin layer of ice on the roadway. Any ice is dangerous to drive on, but black ice is particularly hazardous because the road looks wet, not icy. Black ice isn’t really black; it’s so thin and transparent that the darker pavement shows through. It often has a matte appearance rather than the expected gloss.
Ordinary snow tires are designed for snow, not ice. The most helpful device for gaining traction on ice is tire chains. But even with chains, stopping distance is still several times greater than on dry pavement with ordinary tires.
Black ice is most common at night and very early in the morning, when temperatures are typically their lowest. It is usually thin enough that it melts soon after sunlight hits it, but it can last much longer on shaded areas of roadways. The ground cools more slowly than the air and warms back more slowly as well, so even if the air temperature is above freezing, the roadway may still be frozen. This discrepancy between temperatures can lull drivers into a false sense of security.
Winter Drying Guide PDF from Oregon.gov