There’s a reason tires aren’t hard, smooth donuts that slip easily; tires are rubber with tread designs so that they can grab the road and help us get going when we accelerate and so they can help us stop when we hit the brake pedal.
Over the years, through trial and error, tire makers have designed tire tread patterns that are particularly good for grabbing the road. In some cases, they design tread patterns for auto racing where going fast is more important than stopping. They also make tire tread patterns for use with off-road trucks and SUVs, and they make tread patterns that are better for grabbing the road in the snow and over ice.
The problem with tires is that, in order to grab the road, they’re made of rubber, a substance that is softer than the road, whether the road is made of asphalt or concrete. Off-road trucks and SUVs may drive through mud and rivers but generally they also go over rocks and gravel that is harder than rubber.
As tires go over the road, the road wins a battle of durability. It’s not that the road doesn’t suffer, too. We know it does because of the annual road construction we see on the highways – fixing the damage caused by tires pressed by heavy vehicles at various speeds onto the road. But, the tires wear faster.
Grabbing the road progressively wears rubber off of the tires. As the tires roll down the road, the friction required to grab the road also causes heat. When heated, the rubber is even softer. But, of course, when hotter, and softer, the rubber grabs even better. This is one reason tires don’t grab as well in the winter, though they will heat up after they are driven far enough. But, it’s not just that the cold rubber means the tires are harder; it’s also the substances on the road.
Even in the summer, a wet road after a rain is slicker than a dry road. But, in the winter, moisture on the roadway reacts differently because the lower temperatures changes the moisture from a liquid to a solid, or semi-solid. Crystalized moisture – snow – is problematic for traction, particularly the deeper the snow. As a frozen solid – ice – moisture on the roadway is often treacherous. The real hazard is when the crystals come down on top of the solid – snow on top of ice. Then, you also have black ice – ice you can’t see but that’s just as slippery.
Black ice is often found on top of bridges where the cooling effects of the temperature attacks from the top and, though the bridge material, from the bottom. On days where the ice seems to have melted on the roadways, it may still exist on bridges.
Even before moisture freezes into ice, it can be particularly slippery when mixed with other elements, such as oils that drip from passing vehicles. This is why motorcyclists know they shouldn’t ride down the center of a lane. That’s the part of the road directly below car engines and transmissions where the oil will fall if it leaks.
Oil on the road is slippery in its own right. It’s far more so when it mixes with water on a rainy day.
Another interaction with water that can create a hazardous condition is when there are leaves on the road. This means there is a potential challenge to traction to watch out for in the autumn before winter arrives. When tires hit wet leaves a driver can feel as though they’ve had the rug pulled out from under them.
The first thing drivers can do is to adjust their driving to the conditions, whether they’re dealing with:
The other thing they can do is to give themselves and edge in the battle for traction. This starts with ensuring that the tires, and the tire tread, are still up to the task. When the tires wear to a certain point, the tread pattern no longer substantially improves traction. At that point, the tires should be replaced.
It’s also important to ensure that the tires have proper air pressure and that the suspension and steering systems are in good condition. It doesn’t hurt to have good brakes either (that’s actually imperative).
Over the years, through trial and error, tire makers have designed tire tread patterns that are particularly good for grabbing the road. In some cases, they design tread patterns for auto racing where going fast is more important than stopping. They also make tire tread patterns for use with off-road trucks and SUVs, and they make tread patterns that are better for grabbing the road in the snow and over ice.
Tires are rubber for a reason
The problem with tires is that, in order to grab the road, they’re made of rubber, a substance that is softer than the road, whether the road is made of asphalt or concrete. Off-road trucks and SUVs may drive through mud and rivers but generally they also go over rocks and gravel that is harder than rubber.
As tires go over the road, the road wins a battle of durability. It’s not that the road doesn’t suffer, too. We know it does because of the annual road construction we see on the highways – fixing the damage caused by tires pressed by heavy vehicles at various speeds onto the road. But, the tires wear faster.
Grabbing the road progressively wears rubber off of the tires. As the tires roll down the road, the friction required to grab the road also causes heat. When heated, the rubber is even softer. But, of course, when hotter, and softer, the rubber grabs even better. This is one reason tires don’t grab as well in the winter, though they will heat up after they are driven far enough. But, it’s not just that the cold rubber means the tires are harder; it’s also the substances on the road.
The elements can impede traction
Even in the summer, a wet road after a rain is slicker than a dry road. But, in the winter, moisture on the roadway reacts differently because the lower temperatures changes the moisture from a liquid to a solid, or semi-solid. Crystalized moisture – snow – is problematic for traction, particularly the deeper the snow. As a frozen solid – ice – moisture on the roadway is often treacherous. The real hazard is when the crystals come down on top of the solid – snow on top of ice. Then, you also have black ice – ice you can’t see but that’s just as slippery.
Black ice is often found on top of bridges where the cooling effects of the temperature attacks from the top and, though the bridge material, from the bottom. On days where the ice seems to have melted on the roadways, it may still exist on bridges.
Even before moisture freezes into ice, it can be particularly slippery when mixed with other elements, such as oils that drip from passing vehicles. This is why motorcyclists know they shouldn’t ride down the center of a lane. That’s the part of the road directly below car engines and transmissions where the oil will fall if it leaks.
Oil on the road is slippery in its own right. It’s far more so when it mixes with water on a rainy day.
Another interaction with water that can create a hazardous condition is when there are leaves on the road. This means there is a potential challenge to traction to watch out for in the autumn before winter arrives. When tires hit wet leaves a driver can feel as though they’ve had the rug pulled out from under them.
What can drivers do about challenges to traction?
The first thing drivers can do is to adjust their driving to the conditions, whether they’re dealing with:
- wet roads
- leaves on wet roads
- oily wet roads
- snow on roads
- ice on roads
- black ice on roads
- snow on top of ice on roads
The other thing they can do is to give themselves and edge in the battle for traction. This starts with ensuring that the tires, and the tire tread, are still up to the task. When the tires wear to a certain point, the tread pattern no longer substantially improves traction. At that point, the tires should be replaced.
It’s also important to ensure that the tires have proper air pressure and that the suspension and steering systems are in good condition. It doesn’t hurt to have good brakes either (that’s actually imperative).
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