What Are Stopping Distances In Ice? How To Brake Safely
When driving on ice, you must factor in additional space and time
to brake safely, or else you'll slide. Here are appropriate stopping distances
in ice.
Even the safest, most experienced driver can slide on an icy road. This occurs when you brake your vehicle at the wrong time, without enough distance, or with too much force. Icy roads are a leading cause of accidents, mainly because people are unaware of how stopping distances are dramatically altered by icy conditions.
Sliding can result in injury to the driver and passengers, whether that's collisions between vehicles or from sliding into objects and structures. At the very least, you may need to repair vehicle damage or cosmetic issues that result from losing control.
Luckily, icy roads don't have to be perilous for drivers at random times. Stopping distance exists for a reason, to give drivers:
- Enough time to brake at a gentle pace (which prevents sliding)
- Enough space to slow down gradually while still manoeuvring as intended (which eliminates the need for hard braking)
- Spare distance to regain control of the vehicle should they begin to slide (well before they collide with something)
Let's explore the appropriate stopping distances on ice, so you can drive safely:
What Is Stopping Distance?
Stopping distance is a practice that drivers should employ at all times. This is true in easy driving conditions and difficult ones alike. It's often broken down into a simple formula:
- Thinking distance + Braking distance = Appropriate stopping time
In other words, the right amount of stopping distance is determined by:
- Your reaction time
- How far the car travels after the brakes have been applied, until the point where it stops
Let's say you are driving behind another car. If this car suddenly applies the brakes and slows down, or even comes to a halt, you will first be confronted with your reaction time. How quickly can you realize what is happening, gauge how hard you need to brake, and apply the brakes correctly?
With that allotted time in mind, you now apply the brakes. How long will it take before your car slows down an appropriate amount? How long until it stops completely, so you avoid a collision?
With these two factors, you must now decide how much distance is needed between you and the car ahead of you. It doesn't matter how quickly you react if there is not enough space to slow down and stop. Likewise, responsive braking won't matter if you don't react in time. It's important for you to consider both factors and provide yourself with enough space to drive safely.
For most drivers, this space is car-length between them and the next vehicle. However, when driving in icy conditions, you need far more stopping distance.
This is at least triple the normal amount, but as much as 10 times when driving upwards of 70 mph.
Why Do I Need More Stopping Distance On Ice?
When driving on ice, you're not only accounting for the standard factors that affect stopping distance. You must also account for the lack of traction that ice creates. Here's why:
- Braking too quickly or too hard can lead to sliding. Your tyres will lose their grip on the road when they halt their rotation abruptly.
- As such, you need to brake softly and slowly when driving on ice. This takes extra space, which must be included in your stopping distance. After all, you will be slowing down at a far more gradual pace than normal.
- Not giving yourself this space can lead to you colliding with another car or a structure. You would've stopped before hitting it on normal roads, but on icy ones, you can't slow down fast enough.
- If you do slide, you need extra space so that you can get control of the vehicle before you hit something. The time needed will depend on how fast you're going, how icy the road is, and how much you're sliding. Factor all of this into your stopping distance.
As such, stopping distances in ice should be double the standard amount. However, this may go up substantially, depending on how fast you're going.
Safe Stopping Distances Based On Speed + Conditions
It takes 23 metres to react and brake in dry conditions at 30 mph. The average speed limit on a motorway is 70 mph, so it will take 96 metres to stop in these conditions. The recommended distance between you and the car ahead is a single car-length.
When driving in the rain, you need twice the distance between you and the car ahead. For example, if you're driving at 70 mph on the motorway, then instead of 96 metres, you'll need 192 metres of stopping distance. At a speed limit of 30 mph, it will take 36 metres to stop in wet conditions.
When you are driving in snowy or icy conditions, the stopping distance is an astounding 10 times longer. That's because the risk of sliding is high, and you will need ample space to regain control of your vehicle in this situation. The slower you go, the safer you will be, as you will not slide at the same velocity (which would make it harder to regain control and make any collision far more destructive).
As such, you should avoid driving at 70 mph when the weather is severe. Motorways are often salted and cleared to prevent ice from forming or staying, but it's still encouraged by road authorities to reduce your average speed. After all, if you are driving at 70 mph, it will take a staggering 771 metres to stop.
Even at the speed of 20 mph, it will take 120 metres to stop, so it's important to remain extra vigilant in snowy and icy conditions. Leave as much distance as possible between the cars ahead and yourself.
How To Improve Stopping Distances
To improve your stopping distance – and your overall safety on the road - you can invest in winter tyres.
Winter tyres are designed to grip the road more efficiently, which reduces the chances of sliding. They have additional tread; a specialized, interlocking grip pattern; and a softer composition. This ensures more surface area is touching the road, it provides greater traction at these points, and it prevents loss of contact with the road after sudden braking.
As such, drivers have better control of their vehicle on icy roads with winter tyres. In fact, winter tyres can make driving in bad conditions far more similar to driving in normal conditions. Triple the average car-length is still encouraged as a stopping distance, but the 10-times recommendation is less necessary.
As a bonus, winter tyres exert less effort to maintain their grip on the road, which can reduce fuel costs as well as improving safety. If you want to know more about how to improve your stopping distances in cold conditions, or about driver and tyre safety in general, speak with your local Autofusion experts today. We're happy to provide you with experienced advice and budget-friendly servicing, so you can stay safe year-round.