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By Sgt. Robert Kopczynski


The winter season brings additional driving challenges and hazards, and requires some modifications to our normal driving habits. Ice and snow are two of the most obvious hazards associated with winter driving, but a great deal of winter time accidents also occur on sunny, relatively dry days. The main reason for the majority of traffic accidents during this time of year have to do with longer distances that are required to stop our vehicles. The loss of traction is the cause for longer stopping distances, so it helps to have an understanding of what affects the traction we have available to us as we drive. There are three main factors that affect traction:

Tire Composition – The types of tires you have on your vehicle have a profound influence over the amount of traction you have available to you. The tread design and tread depth are the two most important. During the winter you need a tread design that will allow the tires to grip the snow, which requires many blocks of tread, separated by spaces that allow the tires to "dig in" to the snow itself. The majority of All-Season tires sold today will work well in the snow, but not as well as tires that are specifically designed for snow. All-Season tires have to make a compromise for everything from dry pavement traction, to ice and snow covered pavement, and everything in between. Because of this compromise, All-Season tires never offer the optimum traction for any given road surface. In order to get the most traction from a tire in the snow, a tire designed specifically for use in snow is your best bet. Modern "snow tires" are very different from the snow tires that were made years ago. Modern snow tires are designed to be used in a set of four, and have much better driving characteristics on dry pavement than the older types of snow tires, which would only be used on the drive wheels. For convenience, many after-market tire companies offer a winter tire and wheel package, which makes changing over to snow tires easier. The snow tires are mounted on their own rims, which eliminates the need to remove the regular tires from the rim, and replace them with the snow tires. Besides the tread design, the tread depth is equally important to your available traction. Whether you choose to stay with All-Season tires, or use special snow tires, it is important to check the tread depth. Many auto parts stores sell tread gauges, which give a good indication of tread wear, but a simpler method is by using a penny. Place the penny, upside down, into the space between the treads of the tire. If the tread does not cover the top of Lincoln’s head, the tread is worn low and the tire should be replaced. Tires are also equipped with treadwear indicators, consisting of a bar that runs across the tread. If the bar is visible, and even with the rest of the tread, the tire should be replaced. The easiest way to locate the treadwear indicators on your tires is to look at the sidewall of the tire. As you look around the edge of the tire, you will see four or five triangles. The triangles indicate where the treadwear bars are located.

Road Surface – The road surface that you are driving on is another factor that affects your available traction. If the roadway is new, it has greater traction. If the roadway is old and traffic polished, it will have less traction. There is usually no difference in traction between concrete roadways and asphalt roadways, but both afford more traction than gravel roadways or shoulders. Roadway defects such as potholes can also affect traction. While driving, take a moment to look at the surface you are driving on. If the roadway appears to be older and worn by traffic (Usually has a "shiny" appearance) use extra caution and allow more room to stop your vehicle. Excess oil deposits on the road will also decrease traction, and the same caution should be used.

Environmental Conditions - The obvious environmental conditions that affect traction are rain, snow, and sleet. Other environmental conditions can also affect traction, however; Extreme cold will actually result in less traction from the roadway surface. Cold days also require extra caution when driving over bridges, due to the underside of the road being exposed to the air. Bridges are the first areas of a roadway that will freeze because both the top and bottom of the surface is being hit with the cold air. Once again, greater distance is required to stop your vehicle when any of these environmental factors are present, so more distance should be left between your vehicle and vehicles in front of you.

The best way to allow for longer stopping distances is to slow down. When a vehicle’s speed is doubled, its stopping distance is quadrupled. For example, if a vehicle needs 30 feet to stop at 30 miles per hour, it will need 120 feet to stop at 60 miles per hour. Driving at a slower speed will also allow you a greater distance in which to react to a hazard. The average person’s reaction time is 1to1 1/2 seconds, depending on age and other factors. A driver travelling at 40 miles per hour is travelling approximately 59 feet per second. If a driver travelling at that speed perceives a hazard, and has a 1-second reaction time, their vehicle will travel 59 feet before any evasive action such as braking or steering takes place. If a driver is travelling at 30 miles per hour, they are covering approximately 44 feet per second and will react 15 feet sooner than the vehicle driving 40 miles per hour. Fifteen feet could mean the difference between avoiding an accident, as opposed to being part of one.

A good way to judge the proper distance is the two-second rule. As the rear bumper of the vehicle in front of you passes a stationary object, such as a light pole or sign, count off two seconds. If the front bumper of your vehicle passes the same object within the two seconds, you are too close to that vehicle. Remember that as speeds increase, the distance will be covered more quickly, and more space between the vehicles will be required.

The best way to stay safe while driving during winter is to allow extra time, and slow down. Additional tips for safe driving include:


Avoid distractions such as cellular telephones, reading materials, and the practice of performing personal grooming habits while driving.

Make sure your vehicle is well maintained, and the tires are in good shape.

If your vehicle is equipped with Anti-Lock Brakes (ABS), take the opportunity to familiarize yourself with the way they work. The best way to accomplish this is to find an open area, such as a parking lot, that is wet or covered with snow. Travel at a low to moderate speed (20-25 miles per hour) and apply the brakes as firmly as possible. You may feel a strong pulsating sensation through the brake pedal, this is normal and you should continue to apply the brakes until stopped. The benefit to Anti-Lock Brakes is the ability to steer the vehicle while braking. Practice steering your vehicle while simultaneously braking, it may help you avoid a future accident. When practicing these maneuvers, make sure the area is free from obstructions, such as light poles or other cars.

Always wear your seatbelt, especially in cars equipped with air bags. The air bags in your vehicle are designed to work in unison with the seatbelt system. Not using seatbelts in an air bag equipped car could result in serious injury from the bags themselves.

Never allow a child under the age of thirteen to ride in the front seat of a vehicle equipped with passenger side air bags. The safest place for children is in the back seat, belted in. If children are taught to wear their seatbelts at an early age, it becomes a habit. Wearing your seatbelt is a habit that could save you life!

Winter and the holidays can be a beautiful and fun time of the year, please use these safety tips to get the most out of the season, so you can enjoy more of them in the future.



Bob Kopczynski is a sergeant with one of the Far Western Chicago suburbs, where he has served for eighteen years. Bob is a State Certified Accident Reconstruction Specialist, and a State Certified Driving Instructor responsible for teaching police officers and firefighters throughout the state. He has a Bachelor’s degree in Criminal/Social Justice from Lewis University and is currently working on completing his Masters degree. Bob resides in the western suburbs with his wife and daughter.


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