Winter Driving Tips:
1. Winter Readiness Kit. There are many things that should be kept in a vehicle during the winter season, here is a list of the minimum items:
a. Bottle of water and some food (backpacking meals, food bars, etc)
b. Tire chains and ties
c. Jumper Cables
d. Small tarp to kneel on and many other uses during an emergency
e. Space or wool blanket
g. Road flairs
h. Small shovel
j. First Aid Kit
k. A sandbag or two full of sand
l. A good book…
Other vehicle tips include making sure your vehicle is in good running order and the battery is good. Always keep the gas tank at least half full when traveling, and make sure someone knows where you are going. For more ideas on how to be prepared, search for ideas on the internet.
2. Rain. Rain can make roads slick by reducing tire friction in two ways. The rain can mix with oils on the road forming a slick solution and/or the water can float (hydro-plane) the tires off the road surface if the tire (vehicle) speed is great enough. This can occur at speeds as low as 35mph. When it has not rained in some time, be cautious as the built up oils and water can be very slick even during the summer. And anytime there is water on the road surface, slow down to prevent hydro-planing.
3. Frost. As the temperature drops to near freezing (32° F) the road may develop frost crystals, even though it appears to be bare and dry. This can reduce the traction between the vehicles tires and the road surface. If your vehicle has a thermometer that measures the outside ambient air temperature, when it gets to 33-34° F or lower, slow down and watch for sparkles from the ice crystals on the road and the road’s shoulder. If frost is seen, slow down.
4. Black Ice. When the temperature is near freezing, be cautious of any locations on the road that appears to be wet (the pavement will appear black). This may be what is known as black ice and is extremely slick. Slow down prior to the location. When on the location, do not make any quick changes in movement (jerking the steering wheel, hitting the breaks, etc). Just try to “glide” through the location making no quick movements.
5. Elevation. Typically as you gain elevation the temperature will drop. Dependent on other weather conditions, the drop can be anywhere between 3° F to 6° F per 1000 ft. gained. So even though there is no ice or snow at your location (elevation), if you travel up into the hills, you may very well encounter it, so slow down.
6. Cold Air Sinks. As cold air is heavier then warm air, it can sink down to lower elevations. Some areas such as the Chapman area on Scappoose Vernonia Road are known as a cold air sink areas and may be colder then areas even at higher elevations. The cold air may sit in these areas for days allowing for frost or ice to develop making the roads slick. Watch for frost or snow hanging around in an area longer than other areas, and slow down.
7. Bridges. Bridges have no insulating material under them (soil or rock), thus will frost / freeze faster then the main road surface. When the temperature is near freezing, slow down when approaching and crossing bridges.
8. De-icer. ODOT and the County use chemical de-icer (magnesium chloride) on some roads when the weather conditions are right. Once the road has been sprayed with de-icer, it can remain effective for up to 5 days. Rain will dilute and wash the de-icer off the road, so timing of when to apply it is critical. Also, de-icer is only effective when the temperatures are within 15 ° of 32° F. De-icer is great, but don’t trust it. The de-icer may be old or diluted, or the temperature may be too low for it to be totally effective. So when the temperatures are at or near freezing, slow down.
9. Sanding Rock. ODOT and the County use sanding rock during certain weather conditions. This is the material that is used on most County roads. It is not affected by temperature or rain. However, as each vehicle passes over a sanded road, the tires bounce/throw the sand off the road. After several hours of high volume traffic, most of the sand may have been kicked off the road. So when the temperatures are at or near freezing, even though the road has been sanded, slow down.
10. Shadows and shaded areas. Many areas of our roads may remain in shaded areas throughout the day. In these areas the sun has not had an opportunity to warm the road and melt any frost or ice that may have formed during the night. So during the day, most of the road may be clear of ice and frost, except these shaded areas, which can be extremely treacherous. So when the temperatures are at or near freezing, slow down when coming into a shaded area, even though most of the road is exposed to the sun and is clear and dry.
11. Snow. The road crews work very hard and put in long hours trying to keep the roads clear of snow. However, during large long snow events, that may not be totally possible. When the roads are covered with snow even to the lower elevations, the crews will usually start at the higher elevations, where the problems are greatest, maintaining priority roads first. As the priority roads are opened and cleared, the crews will begin working on secondary roads. During snow plowing periods, only limited sand will be used, and no de-icer. It is not efficient to sand a road, only hours later to again plow that road and throw the previous sand into the ditch with the snow. Use appropriate traction device on tires, slow down, and travel when only necessary.
12. Ice. Ice is extremely slick when the temperature is just a few degrees above or below freezing. When ice is encountered do not contuct any quick movements, as was described in #3. Metal studs or chains/cables on the vehicle tires help, but even they cannot be counted on. When the roads are iced over, it is a very good idea to travel only when necessary.
13. Mud on the Road. Many land use activities can cause mud to be tracked onto the road’s surface. The amount of mud can be anything from just enough to “paint” the road a light brown, to a couple of inches. If the moisture content is just right, the mud can be extremely slick. Watch for activities off the road that may drag mud onto the road’s surface. When such activities are seen, slow down in anticipation of encountering slick mud.