There's a lot more to good emergency braking than knowing which pedal to push. By following a few basic rules we can optimize stopping ability even in an unfamiliar car.

Rule 1. Cars stop best in a straight line. That's the only time all the available traction is available for braking.

Rule 2. On virtually every production car there is an initial free play in the brake pedal that doesn't contribute much to stopping.

The driver needs to quickly reach the hard spot in the pedal when threshold braking or lock up occurs which can be anywhere from a third to two-thirds of the way through the total pedal travel.

Rule 3. Threshold or maximum braking occurs when the tires are turning slightly slower than the vehicle speed. This should generate a scuffing sound or some squealing of the tires, but not the howling that occurs when a tire is locked.

Rule 4. Locking up the wheels increases stopping distance by about twenty-five percent, makes steering impossible, ruins the tires and scares everybody in the area.

Rule 5. A locked tire can be freed to roll again without going to the extreme of pumping the brakes. A slight reduction of pressure on the pedal is all it takes. We refer to this as modulation.

Rule 6. While large leg muscles can get you to the hard spot with a firm press, more sensitive foot muscles have to deal with pressure control for the rest of the stop.

Rule 7. Pumping the brakes is outdated, inefficient and upsets the car's balance.

Rule 8.The faster a car is going, the harder the brakes must be pressed in order to reach threshold, which we'll call a number 10 pedal (that would be ten out of ten). To maintain this perfect level, brake pressure would have to be reduced slightly throughout the stop.

Rule 9. Knee position — shifting the knee towards the left — serves to line up the joints from hip to ankle and permits more precise use of the foot muscles.

Rule 10. If a car is being braked with a perfect number 10 pedal and any steering input is needed, brake pressure must be reduced accordingly. Otherwise, there would be no traction available for turning. Anti-lock brakes perform this function electronically, as well as preventing wheel lock-up in straight line braking.

An analogy we often use in the Dodge/Skip Barber Driving School is to imagine a string connecting the right foot and the steering wheel. As the wheel is turning, the string tightens, smoothly pulling the driver’s foot back. If the string unwinds, the driver's foot can press harder on the pedal.

The Perfect Stop
Let's put this together and create a perfect stop. An incident occurs and the driver goes quickly to the brake pedal, pressing and squeezing up to a number 10 pedal. As the car slows and kinetic energy is reduced, the front wheels start to lock, but the driver curls the right foot back about a quarter of an inch and the wheels start to turn again. There's a car blocking the lane ahead and our driver needs to steer, but stopping is still the goal. As the wheel is turning the foot curls back a bit more, smoothly balancing grip between the two tasks of turning and braking. The car stops safely, out of harm's way.

The same incident, with an anti-lock brake equipped car, would be dealt with in a similar fashion. Once the driver has activated the anti-lock brakes there's no point second-guessing the system. Keeping the wheels straight for as long as possible will maximize braking power. When the wheel is turned, the anti-lock system will perform the balancing act, keeping the wheels rolling and balancing available traction between the two tasks. In effect, anti-lock brakes give every driver an educated foot, something professional drivers spend years practicing and perfecting.

Better Anti-lock Braking
It's worth noting, though, that anti-lock brakes can fail and also that it's possible to optimize their performance by understanding the physics involved. The more cornering force needed, the less traction available for braking. In some emergency swerves, the driver may need all the car's traction to make a lane change, so braking would not be possible.


Hand Versus Foot Position
In order to be able to drive through corners safely and efficiently we need to be aware that hand position — what the driver is doing with the steering wheel — and foot position — which pedal is being depressed and how much — are closely linked.

Power and Steering
In our discussion of load transfer we dealt with the idea that acceleration generally reduced the traction available for steering. From this it's possible to reach a simple and elegant conclusion — if we want to keep our car balanced, we cannot add significant amounts of power while we're holding or adding steering. If we do, we're contradicting one input for another, binding up the car.

The Key to Acceleration
When can we accelerate? We can add power at the point where we begin to reduce the amount of steering as we approach the exit of the corner. It makes perfect sense. Of course, few drivers are aware of this rule and in everyday driving it probably isn't that critical, since we're well below the vehicle's ultimate potential. Remember though that we're trying to create good habits, and even at slower speeds there is a great deal of satisfaction to be derived from driving with good timing.

Avoid Entering Too Fast
Racing drivers and street drivers share a common goal in negotiation of a corner: they want to get through the turn and onto the straightaway. As basic as this sounds, excessive optimism in the form of too high an approach speed can make this a difficult task.

There are few worse things that can be done with a car than entering a corner too fast. If speed is truly excessive, the car simply will not stay on the road. The laws of physics win out and even the world's best driver can't change that. Therefore the wise approach is "slow in/fast out" on the track, or more realistically, "slow in/safe out" as a policy on the street.

Cornering Techniques
In the Dodge/Skip Barber Driving School, though, we have the opportunity to work on cornering techniques and explore the car's limit. We learn to fix the kind of errors that might occur in everyday driving where a corner turns out to be tighter than it looked, a sudden bump throws the car off line or perhaps a dog leaps in your path as you round a blind turn.

A driver's first task is to prepare the car for a turn, and this means slowing down in a straight line for maximum braking efficiency. This spot at which the brakes are first applied is called, appropriately, the braking point.

In a manual gearbox car any downshifts should be done in a straight line as well. The clutch should never be depressed during a corner. The brakes may be released before the turn but in most cases trailing the brake a little into the turn will help keep the car more stable. The driver is already looking through the turn and in fact has looked before turning the wheel. In a tight turn this may mean sighting through the side window.

The purpose is to gain information first, then use it. This is a great way to avoid surprises. The driver's foot transitions smoothly from the brake to the accelerator, assuming the view is clear, and then the accelerator is squeezed smoothly down as the driver dials out the steering. Note the terminology — we're not talking about stomps, slams, kicks or punches. Good driving has its own vocabulary with words like trail, feather, modulate and squeeze.

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Shuffle Steering
Our preferred method of adding and reducing steering is called shuffle steering. If you're willing to devote the effort to practice this technique the result should be more precise steering, more accurate skid control and a generally calmer driving environment.

Here's how it works. For a left turn, the right hand moves to the bottom of the steering wheel then pushes the wheel up a full half turn. This places the right hand at the top of the wheel. Meanwhile, the left hand has mirrored this movement and slid up to meet the right. The left hand now pulls the wheel down through another full half turn, while the right slides down the wheel rim so both hands meet at the bottom.

The Advantages of Shuffle Steering
Both hands stay on the wheel at all times.
The hands never cross over or get jammed on the wheel. (Whatever technique you've used, try and reposition your hands so they are close to nine o'clock and three o'clock when cornering.)
The driver is able to steer without leaning and losing contact with the seat back.
There is less flailing around of arms than in hand-over-hand so the driver retains a better sense of where the wheels are pointed. This is especially significant during skid recovery.
The driver retains the stability to feed the wheel back to center after a turn, rather than letting it slip through the hands.
The Don'ts
One of the worst habits we see in traffic is the tendency to steer with one hand on top of the wheel, the other often resting on the gear lever. You'd be hard pressed to find a less efficient position, either for getting good feedback from the car or for control in an emergency. Rest assured that there is no need to hold on to the shifter, either. The transmission won't fall out if you let go. Finish the shift then put the hand back on the wheel where it belongs.

Now that more cars are airbag equipped, this position also means that if the airbag deploys you'll have a brief and nasty fistfight with yourself as your arm is thrown backwards.

This is also a good reason to have a hands-free phone if you must use a cellular phone while driving. Many states are now making it illegal to drive while holding a phone in part for this reason. Drinking from a hand mug or smoking a pipe while driving could also be classified as bad ideas.


Learning to Put the Traction Where You Need It
There are three main elements of vehicle dynamics that a driver should understand. The first of these is load transfer.

Load Transfer
Let's assume we're starting with a car that's either at rest or balanced at a steady speed. The load, and therefore the traction, is equally distributed at the four corners of the vehicle. Any control movement, even the slightest twitch, will transfer load from one corner to another. The footprint of the unloaded tire will lose traction, while the loaded tire will gain traction. If we accelerate, the rear tires gain grip while the front lose grip. Under braking, the effect is reversed.

Power and Traction
A logical conclusion would be that if we are accelerating hard, there might be less traction available for steering. This is true regardless of whether the car is front- or rear-wheel drive. It's important to understand though that this doesn't mean we coast through corners. Balanced throttle, or steady power, can be useful in many situations. However, excessive power through a corner is not a good idea. Even if you get away with it, you'll be developing bad habits.

Stored Energy
The second key to understanding driving is the principle of stored energy or spring rebound. Any time a car changes either speed or direction, springs are either compressed or extended. The return or rebound of those springs can upset the car's balance, leading to the dreaded fishtail effect where the car's back end begins to wag uncontrollably. A good driver will anticipate this phenomenon and be ready to calm the whole process with careful, well-timed control applications.

The Keys to Control
Finally, a good driver should recognize that cars have three rudders, three controls that either alone or together can be used to change direction. These three rudders are the brake pedal, the throttle pedal and the steering wheel.


Slip
Any time a car is cornering, even at fairly sedate speeds, there's some discrepancy between where the tires are pointed and where the car is headed. This is just the normal effect of tire scrub. As forces rise, though, the tires start to slip more relative to the car's direction of travel.

For example, if the front tires are losing traction due to power understeer, the tires may be pointed towards the inside of a corner while the car is plowing towards the outside. The tire's direction represents hope while the car's direction of travel represents reality. The difference between hope and reality is known as the slip angle.

Slide
In high-performance driving, we often use controlled slides, or slip, to direct the car. As a result, we usually hear a degree of tire noise. This isn't necessarily a bad thing, it just means the tires are working fairly close to their limit.

Skid
When a slide becomes a skid, though, it means we have exceeded the traction potential of the tire and it is beginning to break away. At this point the slip anglewill increase dramatically and if the driver responds quickly the result will be a loss of control. When tire squeal becomes very loud on dry pavement chances are the limit is near. On wet pavement, though, there will be little if any tire noise to serve as a warning and the only squealing may come from the driver or passengers.

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STICKY!