Don't skid! Duh!
Brake smoothly. How?
Give yourself lots of room. How much is that?
Steer smoothly.. Don't I do that now?
You've heard these all before when people are telling you how to drive in the winter with rain, snow, ice and poor visibility.
"But don't I already avoid skidding, smoothly steer and brake? How much room is lots?"
If you want those answers, I'll tell you honestly and frankly: you don't have the math or the computer to get the answer. You won't get an answer fast enough to help you. Expert drivers do it by feel, intuition and seat of the pants.
Not much help? No, but I'll give you a better way than giving up and hoping for the best. You can drive like an expert. There is a secret which if you apply you'll avoid accidents and panics. You'll even learn to enjoy winter driving. But when you learn the secret, a lot of what they told you in drivers ed will look wrong. Why Because it is.
THE SECRETS
Cars are dumb. There is no part of your car that makes a decision or knows whats going on That's why you have to get in the car. You are the brain, eyes and accelerometer. If you don't see it or feel it, the car won't do anything about it. Be aware.
Only one part of the car sticks to the ground. Your tires are important. In winter, they are your best friend. Your car never performs better than your tires. Your tires tell you what the road does. Your tires make the car do what you want to do.
The traction circle
Cars move by friction. There are two kinds of friction: static and dynamic. Static friction works when two surfaces touch and don't move relative to each other. Static friction calculated as a fraction of the weight applied to the wheel. If friction is 100% then the full weight of the wheel is available for car control. If it is 0, you have no control. Most sedans have static friction coefficients of about 70% on dry pavement. Sports cars have up to 90%. High performance cars reach 120%. Formula One racers approach 500% . On wet pavement a sedan will be about 40-50%. On snow 10-25%. On hard ice 1%.
Dynamic friction is what we are worried about most when we drive. It is sometimes called rolling friction. Its a bit smaller than static friction but is the biggest part of traction.
You need traction to turn, accelerate, or stop. To accelerate or brake twice as fast you need four times the traction or four times the distance. The most traction you can get is the weight on the tire times the friction coefficient. Imagine drawing a circle that big. Put a arrow from the center in the circle that is as long as the traction you are using. If you turn left is points left. If you turn left harder it points left and gets longer. If you turn right even harder, it points right and grows until it hits the circle. After it hits, you skid. If you put the brakes on it point up. If you accelerate it points down. Any combination of turning, braking and accelerating gives you positions between 12, 3, 6, and 9. For example if you brake and turn left it points to 10:30 when the forces are equal.
Suppose you brake as hard as you can without skidding and then you add a hard turn to the right. The arrow points to 1:30 but it has to stay as long up and down as it was at 12:00, so even if you aren't braking any harder the tip of the arrow has to go out of the circle and you skid. This is the next secret: you can turn really hard or accelerate hard or brake hard but you can't do them at the same time. So, coming to a turn in snow, brake in a straight line until there is no doubt you can make the turn without brakes. Accelerating in snow, keep it straight until you are up to speed. Turning in snow, don't use your brake (until you learn the advanced techniques)or accelerate.
Driven Wheels
Front wheel drive (FWD) uses the front tires most, rear wheel drive (RWD) uses the back wheels for acceleration and braking, but the front wheels for turning and braking. All wheel drive (AWD or 4WD) uses all of the wheels for braking and acceleration but the front wheels for turning. You don't get any better traction with AWD than FWD or with RWD and a center engine.
Focus
When you drive, your eyes' focus should move further in front of you as you go faster. You naturally want to go where you look. It is easy to move the car where you look. Don't look at curbs near you, don't look a dotted lines. Look yourself around corners. It's Much easier.
At 60 mph your focus should be 175 feet in front of you (about 10 car lengths) on a clear road and 200 feet in front on a congested road. Remember, at 60 mph, you can't avoid hitting anything closer than 88 feet to you if it is at the same speed and twice that if it is stopped.
It's 176 feet to stop on dry pavement, on snow 352 feet at 60 mph, on ice 6300 feet or 460 car lengths minimum. Those long stopping distances in winter are why brakes won't help you much, your best choice is turn to avoid. On ice you can swerve at about a half a foot per second, enough to avoid a car in 15 seconds, braking would take 65 seconds.
Prepared
So now that you are smart about snow, how do you put it all together?
1. Buy good tires, deep tread in the middle, aggressive pattern on the edge. You brake on the middle tread, you steer on the edges
2. Fix steering, braking and engine control problems before winter. Ignoring it is like dancing on shoes that are falling apart.
3. Practice. Work on controlled smooth curves in dry weather. Increase you speed around the corner as you improve. You should be able to balance a half full cup of water on your lap.
4. Skid. Find an empty lot and practice figure eights. Go faster until you do skid. Remember that speed (don't look at the speedometer, use your vision). You need to develop firm, controlled responses to the departures from your path. Skid again but correct it. Know why you skidded: which wheel slipped first?
5. Go-brake-turn. Don't mix them.
6. Repeat in snow.
7. Repeat on ice
ADVANCED.
Sit properly. Legs as straight as possible when the brake or accelerator are on the floor. Support your entire back on the seat. Seat belt low and snug. In a automatic transmission spread your legs to give you a firm base.
Adjust your wheel so that your arms are slightly bent. Now cross your hand so they are on the opposite side of the wheel for the normal position: your arms should make an "X". You should not have to lean away from the seat to reach these positions. Adjust seat and steering wheel as required. Do not grab the wheel. Put your hands gently on the outside of the wheel at 9:00 and 3:00 with it touching the outer edge to your palm from the base of your first finger to the opposite side of your wrist. Gently wrap your fingers around the nubs on the opposite side. Keep your thumbs out of the inside of the wheel, you'll break or sprain your thumbs in a collision if they are inside.Caress the wheel do not choke the life out of it. You get less power to turn the wheel be gripping it hard and you give up fine control.
Now that you are smooth, learn expert techniques. Learn how to keep the arrow tip right on the circle, neither skidding nor under performing
Learn from an expert. Advanced driving is like dancing. I just can't tell you in a way you'll understand but you will learn by doing it with me.
Get some slalom time.. Practice running at the edge of your and your car's capability. You'll find there is space between max performance and total loss of control that you can use. This bit of territory can save your life, if you are familiar with it.
Learn how to fill the corners of the circle. There should be no part of a curve where you are not braking firmly or accelerating strongly. No coasting.
Learn how to pick and hit an apex. Following the lines is the worst path you can take.
Learn trail braking. It fills the entrance to a corner.
Learn why you get on the gas at the apex. Don't stumble out of your turns.
Learn how to under-steer and over-steer. This is car control, mixing a bit a near-skidding with control.
Learn two foot pedal technique. You travel about 50 feet with no input if you move your right foot from gas pedal to brake. How much is that worth in a crisis?
Practice. The difference between accident and near-accidents is familiarity with how your car acts at its limits. Foreknowledge give you the right reflexes and avoids panic. Panic produces momentary paralysis and often leads to the exactly wrong response. Practice lets you control and think when you are asking the most. The chance you you being a skilled driver without practice is the same as being a skilled quarterback without practice- nearly zero.
Brake smoothly. How?
Give yourself lots of room. How much is that?
Steer smoothly.. Don't I do that now?
You've heard these all before when people are telling you how to drive in the winter with rain, snow, ice and poor visibility.
"But don't I already avoid skidding, smoothly steer and brake? How much room is lots?"
If you want those answers, I'll tell you honestly and frankly: you don't have the math or the computer to get the answer. You won't get an answer fast enough to help you. Expert drivers do it by feel, intuition and seat of the pants.
Not much help? No, but I'll give you a better way than giving up and hoping for the best. You can drive like an expert. There is a secret which if you apply you'll avoid accidents and panics. You'll even learn to enjoy winter driving. But when you learn the secret, a lot of what they told you in drivers ed will look wrong. Why Because it is.
THE SECRETS
Cars are dumb. There is no part of your car that makes a decision or knows whats going on That's why you have to get in the car. You are the brain, eyes and accelerometer. If you don't see it or feel it, the car won't do anything about it. Be aware.
Only one part of the car sticks to the ground. Your tires are important. In winter, they are your best friend. Your car never performs better than your tires. Your tires tell you what the road does. Your tires make the car do what you want to do.
The traction circle
Cars move by friction. There are two kinds of friction: static and dynamic. Static friction works when two surfaces touch and don't move relative to each other. Static friction calculated as a fraction of the weight applied to the wheel. If friction is 100% then the full weight of the wheel is available for car control. If it is 0, you have no control. Most sedans have static friction coefficients of about 70% on dry pavement. Sports cars have up to 90%. High performance cars reach 120%. Formula One racers approach 500% . On wet pavement a sedan will be about 40-50%. On snow 10-25%. On hard ice 1%.
Dynamic friction is what we are worried about most when we drive. It is sometimes called rolling friction. Its a bit smaller than static friction but is the biggest part of traction.
You need traction to turn, accelerate, or stop. To accelerate or brake twice as fast you need four times the traction or four times the distance. The most traction you can get is the weight on the tire times the friction coefficient. Imagine drawing a circle that big. Put a arrow from the center in the circle that is as long as the traction you are using. If you turn left is points left. If you turn left harder it points left and gets longer. If you turn right even harder, it points right and grows until it hits the circle. After it hits, you skid. If you put the brakes on it point up. If you accelerate it points down. Any combination of turning, braking and accelerating gives you positions between 12, 3, 6, and 9. For example if you brake and turn left it points to 10:30 when the forces are equal.
Suppose you brake as hard as you can without skidding and then you add a hard turn to the right. The arrow points to 1:30 but it has to stay as long up and down as it was at 12:00, so even if you aren't braking any harder the tip of the arrow has to go out of the circle and you skid. This is the next secret: you can turn really hard or accelerate hard or brake hard but you can't do them at the same time. So, coming to a turn in snow, brake in a straight line until there is no doubt you can make the turn without brakes. Accelerating in snow, keep it straight until you are up to speed. Turning in snow, don't use your brake (until you learn the advanced techniques)or accelerate.
Driven Wheels
Front wheel drive (FWD) uses the front tires most, rear wheel drive (RWD) uses the back wheels for acceleration and braking, but the front wheels for turning and braking. All wheel drive (AWD or 4WD) uses all of the wheels for braking and acceleration but the front wheels for turning. You don't get any better traction with AWD than FWD or with RWD and a center engine.
Focus
When you drive, your eyes' focus should move further in front of you as you go faster. You naturally want to go where you look. It is easy to move the car where you look. Don't look at curbs near you, don't look a dotted lines. Look yourself around corners. It's Much easier.
At 60 mph your focus should be 175 feet in front of you (about 10 car lengths) on a clear road and 200 feet in front on a congested road. Remember, at 60 mph, you can't avoid hitting anything closer than 88 feet to you if it is at the same speed and twice that if it is stopped.
It's 176 feet to stop on dry pavement, on snow 352 feet at 60 mph, on ice 6300 feet or 460 car lengths minimum. Those long stopping distances in winter are why brakes won't help you much, your best choice is turn to avoid. On ice you can swerve at about a half a foot per second, enough to avoid a car in 15 seconds, braking would take 65 seconds.
Prepared
So now that you are smart about snow, how do you put it all together?
1. Buy good tires, deep tread in the middle, aggressive pattern on the edge. You brake on the middle tread, you steer on the edges
2. Fix steering, braking and engine control problems before winter. Ignoring it is like dancing on shoes that are falling apart.
3. Practice. Work on controlled smooth curves in dry weather. Increase you speed around the corner as you improve. You should be able to balance a half full cup of water on your lap.
4. Skid. Find an empty lot and practice figure eights. Go faster until you do skid. Remember that speed (don't look at the speedometer, use your vision). You need to develop firm, controlled responses to the departures from your path. Skid again but correct it. Know why you skidded: which wheel slipped first?
5. Go-brake-turn. Don't mix them.
6. Repeat in snow.
7. Repeat on ice
ADVANCED.
Sit properly. Legs as straight as possible when the brake or accelerator are on the floor. Support your entire back on the seat. Seat belt low and snug. In a automatic transmission spread your legs to give you a firm base.
Adjust your wheel so that your arms are slightly bent. Now cross your hand so they are on the opposite side of the wheel for the normal position: your arms should make an "X". You should not have to lean away from the seat to reach these positions. Adjust seat and steering wheel as required. Do not grab the wheel. Put your hands gently on the outside of the wheel at 9:00 and 3:00 with it touching the outer edge to your palm from the base of your first finger to the opposite side of your wrist. Gently wrap your fingers around the nubs on the opposite side. Keep your thumbs out of the inside of the wheel, you'll break or sprain your thumbs in a collision if they are inside.Caress the wheel do not choke the life out of it. You get less power to turn the wheel be gripping it hard and you give up fine control.
Now that you are smooth, learn expert techniques. Learn how to keep the arrow tip right on the circle, neither skidding nor under performing
Learn from an expert. Advanced driving is like dancing. I just can't tell you in a way you'll understand but you will learn by doing it with me.
Get some slalom time.. Practice running at the edge of your and your car's capability. You'll find there is space between max performance and total loss of control that you can use. This bit of territory can save your life, if you are familiar with it.
Learn how to fill the corners of the circle. There should be no part of a curve where you are not braking firmly or accelerating strongly. No coasting.
Learn how to pick and hit an apex. Following the lines is the worst path you can take.
Learn trail braking. It fills the entrance to a corner.
Learn why you get on the gas at the apex. Don't stumble out of your turns.
Learn how to under-steer and over-steer. This is car control, mixing a bit a near-skidding with control.
Learn two foot pedal technique. You travel about 50 feet with no input if you move your right foot from gas pedal to brake. How much is that worth in a crisis?
Practice. The difference between accident and near-accidents is familiarity with how your car acts at its limits. Foreknowledge give you the right reflexes and avoids panic. Panic produces momentary paralysis and often leads to the exactly wrong response. Practice lets you control and think when you are asking the most. The chance you you being a skilled driver without practice is the same as being a skilled quarterback without practice- nearly zero.
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