Welcome to the Highway Safety School
This unique drivers' school is
designed to introduce you to the fundamentals of car control and driving
mechanics in a safe environment. We've constructed a series of driving
exercises that are designed to provoke certain behaviors from your car. Each
exercise illustrates a particular characteristic response of your car to road
conditions and driver input. You'll learn proper and improper driver inputs for
particular situations. By the end of the day, you'll understand how your car
behaves under braking and cornering, and consequently you'll be a much better
driver.You will be scheduled for track, classroom, and skidpad sessions. Classroom
sessions will cover the underlying principles behind each of the on-track
exercises: what your car's tires are doing while you're negotiating the
exercise, how your steering and acceleration inputs affect your car's behavior,
and why some of your inputs work and some don't. Skidpad sessions will allow
you to experience and practice recoveries from loss-of-adhesion situations in a
safe, controlled, low-speed setting. You'll also learn why your instincts in
such situations are almost always wrong.
This publication describes the purpose of the on-track exercises we'll be
doing; refer to the track map on the last page for the exercise locations. In
the morning, we'll do the exercises while driving counterclockwise, so that the
turns will come up in ascending numerical order. In the afternoon, we'll run in
the opposite direction. Each on-track exercise will involve guiding your car
through a series of "mini-cones," or pylons.
Don't worry about hitting the pylons we use to mark the exercises. They're
only six inches high and made of soft plastic, so they won't hurt your car.
What may hurt your car is if you lose control while trying to avoid
hitting a pylon. Always maintain control of your car, even if it means
running over every pylon on the track!
Before we begin, let's take a few moments to understand what actually
happens when driving. Most of us don't think about driving; it's enough that
when we point our car in a certain direction and step on the accelerator, the
car goes where it's pointed. As long as nothing goes wrong, that's sufficient.
However, our lack of knowledge hurts us in emergency situations.
You've probably lost control of your car at some point in time. Perhaps it
was raining or snowing; you entered a curve a little too fast, turned the
wheel, but your car kept going straight ahead. Or maybe you had to jam on your
brakes suddenly and hope that you'd stop before hitting the car in front of
you. In any case, you know that helpless feeling of being "along for the ride"
with no control over what's happening.
What went wrong, of course, was that you asked your car to do something it
couldn't do, either negotiate a curve at too high a speed or come to a stop in
too short a distance. Physical laws govern the behavior of your car, and
understanding those laws is the key to controlling your car. At the school,
we'll show you--and let you experience--the physical limits of your car's
ability to turn or stop. Most importantly, by experiencing and understanding
these limits, you'll know what options you have in an emergency.
Fundamentally, driving is all about friction: specifically, the friction
between your tires and the pavement. When you depress the accelerator, or apply
the brakes, or turn the steering wheel, your tires generate frictional forces
which are applied to your car to accelerate, decelerate, or change directions.
Each specific demand you make on your car (e.g., turning a corner) requires a
certain amount of force. Your car requires the least amount of friction with
the pavement when traveling in a straight line at a constant speed.
Accelerating, braking, or turning require more friction, with larger speed or
direction changes (e.g., braking harder or turning sharper) requiring
proportionally larger amounts of friction. If your tires cannot generate
sufficient frictional force, your car will not do what you want.
When you apply your brakes, the frictional forces generated by your tires
act to slow your car down. The harder you press on the brake pedal, the larger
the generated force is, and the faster you slow down--to a point. If you press
too hard, your tires will be unable to generate the force being demanded of
them, and they will lock (i.e., stop turning and begin sliding along
the pavement). This sliding still generates some friction, but it is important
to note that it is less than the amount that was being generated just
before they locked.
Therefore, the quickest way to slow your car is to depress the brake pedal
with as much pressure as is possible without locking your tires. This technique
is called threshold braking. It is difficult to modulate precisely the
amount of pressure you apply to the brake pedal, and it's even tougher if
you're trying to turn the car at the same time. However, if you brake with the
ball of your foot, you'll have a lot more control.
Because untrained drivers have difficulty braking with maximum
effectiveness, antilock braking systems (ABS) were invented. If you apply too
much brake pedal pressure, the ABS will modulate the pressure for you; you can
feel this as a pulsation in the pedal and hear it as a chattering noise.
If your car is equipped with ABS, you can always just mash down on the brake
pedal, steer, and let the ABS do all of the work for you. However, true
threshold braking, i.e., applying maximal braking just before the ABS
kicks in, will result in slightly shorter braking distances. Therefore, you
should learn and practice threshold braking by modulating the pedal pressure to
keep the ABS from activating. We've designed three exercises that involve
threshold braking to help you develop this important technique.
Two important aspects of your car's handling are balance and
weight transfer. Balance is how your car's weight is distributed from
front to rear and from side to side. The weight of your car generates
proportional frictional forces (i.e., grip) at each tire, and these
forces change profoundly when you accelerate, decelerate, or change direction;
this is called weight transfer.
When you accelerate, weight transfers to the rear of your car, decreasing
the grip available to your front tires and increasing the grip available to
your rear tires. When you decelerate, weight transfers to the front of your
car, enhancing front tire grip and decreasing rear tire grip. In a turn, weight
transfers to the outer tires, reducing the grip of your inner tires. The amount
by which grip changes at each tire in response to weight transfer is determined
primarily by your car's suspension and its reactions to your inputs.
For a given corner taken at a given speed, each of your tires requires a
certain amount of grip to maintain adhesion with the pavement. Higher speeds
and tighter corners require correspondingly more grip. If weight transfer
causes the grip available at a given tire to decrease below that which is
required, it will lose adhesion and begin to slide against the pavement. If the
sliding tire is at the front of your car, your car will understeer; if
it is at the rear, your car will oversteer.
Understeer, or "push," occurs when your front tires lose adhesion
with the pavement. Instead of following your intended path around the turn,
your car will begin to run wide, as though you were steering less than you
needed to. Understeer is often caused by entering a turn too fast or by turning
the steering wheel too quickly: both upset the balance of your car.
The important thing to realize is that understeer occurs because your front
tires are overloaded; they require more grip to maintain adhesion than is
available. Steering more, i.e., trying to turn a tighter arc, simply overloads
them more, making the understeer worse. To correct understeer, you must restore
adhesion to the front tires by slowing your car and/or straightening the
steering wheel; both reduce the grip required. Straightening the wheel is
counterintuitive, because you're deliberately steering toward the outside edge
of the pavement, but you must regain front-end adhesion before you can
change your car's direction.
Oversteer, or "looseness," occurs when your rear tires lose
adhesion with the pavement. Instead of following your intended path around the
turn, your car will begin to rotate around your front tires, as though you were
steering more than you needed to. To stop the rotation of your car, you must
apply a countering force by steering toward the outside of the turn. You must
also maintain your speed or accelerate slightly. This too is counterintuitive,
because the last thing you'll think you need at that point is more speed.
However, when you accelerate, you transfer weight back onto your rear tires,
giving them more grip. It's important to recognize here that you're applying
acceleration not to increase your speed, but to restore your car's balance.
Oversteer is often caused by sudden deceleration in a turn, either by
braking or by coming sharply off the accelerator, causing weight to transfer
away from the rear wheels. This often occurs when you enter a turn too fast;
the solution is to enter more slowly, so that you can maintain your car's
balance throughout the turn.
Oversteer in a rear-wheel drive car can also be caused by applying enough
acceleration to break the rear wheels loose. This occurs most frequently under
conditions of reduced adhesion (rain), but it can also occur under good
conditions if your car is powerful enough. In this case, you must reduce your
acceleration slightly to allow your rear tires to re-adhere. If you
reduce your acceleration too much or too rapidly, weight will transfer away
from the rear, and your car will continue to oversteer. To avoid inducing
oversteer, it's important to apply acceleration smoothly and progressively.
Remember: anything you do to upset your car's balance may transfer enough
weight to cause understeer or oversteer. That's why we will emphasize
smoothness throughout your school.
We've designed five exercises that demonstrate weight transfer in various
ways. Your skidpad sessions are also designed to demonstrate understeer and
oversteer and the techniques used to overcome them.
Where to Look
Whenever you're driving, you should watch where you're going. This
seems obvious, but you'd be surprised how much time you spend looking at where
you are, e.g., at your hood or at the bumper of the car in front of you. At the
school, we've marked the exercises with pylons, and it's very important not to
look at the pylon you're passing but rather at the next pylon coming
up. Because of the delay between the time you see something and when you react
to it (called your reaction time), you must look and think ahead to
avoid problems. The farther ahead you look, the more time you have to react to
trouble, and the easier it will be to avoid.
Morning On-Track Exercises
Just prior to your on-track session, we will have you bring your car down to
the "false grid" and line up to await your instructor, who will join you before
you start. Only one car at a time is allowed to run a given exercise, so
instead of having everyone wait in a long line at the first exercise, we will
break your group into fourths. You may be directed to bypass one or more
exercises before you start your session; your instructor will tell you at which
exercise you will begin.
There will be double pylons, called staging points, at the side of
the track before each exercise; most will be manned by course workers. Except
when initially bypassing, come to a full stop at each manned staging point
until directed into the exercise by the worker. The two threshold braking
exercises (Exercises 4 and 7) have staging pylons but are unmanned. You only
need to stop at an unmanned staging point if the exercise is occupied;
otherwise, proceed past the staging point immediately.
Exercise 1--Slalom (Pit Straight)
A slalom is a set of spaced pylons located
on the centerline of the track. The object is to drive around the pylons,
alternately passing them on the left and right, while holding a constant speed.
After each successful pass though the slalom, increase your speed a little
As your speeds increase, you'll find it harder to avoid running over the
pylons. This is because your car requires a finite amount of time from the
moment you turn your steering wheel until your car actually changes direction
(called the transient response time). First, the sidewalls of your
tires must flex. Then the springs and bushings in your suspension must
compress. Finally, your car will begin to change directions. The faster you go,
the more distance you cover before your car reacts to your steering input.
The key, then, is to anticipate this delay in your car's reaction
and turn slightly before you reach the next pylon, much as a skier turns his
skis just before a gate. The faster you go, the earlier you will have to
When you turn your car from side to side, you are transferring weight to
alternate sides of your car. In doing so, the springs on the side opposite the
direction you're turning (called the loaded side) will compress. Until
your suspension has fully compressed, your loaded-side tires will not achieve
full adhesion. Final compression will occur most rapidly if the turn is
executed smoothly; if you turn abruptly, your loaded-side springs will actually
compress too much, then expand again (or rebound) before finally
settling down. During this time, you will not have effective control of your
If you enter the slalom too quickly, you will find that you must slow down
to negotiate the first turn. However, when you decelerate, weight transfers
forward, and your rear tires lose adhesion. If enough weight transfers forward,
you could spin.
Moreover, any errors in placement that you make will multiply at each turn.
That is, if you are late turning for the first pylon, you will have to make a
sharper turn at the second to avoid hitting the pylon. If you're going too
fast, you won't be able to make the turn sharp enough, so you'll be late for
the second as well, and the third turn will have to be even sharper. This can
easily cascade, and unless corrected, you may run off the pavement near the
To execute the slalom properly, you must enter at a speed slightly slower
than you think is necessary, smoothly turn the steering wheel slightly ahead of
each pylon, and maintain or slightly accelerate to keep the weight balanced
from front to rear. If you find yourself going too fast, recognize the symptoms
early and abort the slalom by straightening your wheel instead of turning back
for the next pylon. Run over one or more pylons if needed but maintain
control of your car.
Once you're through the slalom, proceed slowly around Turn 1 and through the
Esses to the staging point for the next exercise, which is another slalom, but
this time in a turn.
Exercise 2--Slalom Through a Curve (Turn 4)
The second exercise is similar to the first, but this time,
you'll be going through a curve at the same time. When driven counterclockwise,
Turn 4 is an increasing-radius turn; that is, it starts "tight" and
gets easier to negotiate as you go through it. However, you'll be negotiating a
slalom as you drive through the turn. Whereas the straight-line slalom requires
you to steer right and left with a similar amount of steering input in each
direction, this slalom will require much more steering input and effort to turn
left than to turn right. This is because the road curves to meet you when you
turn right. As with the straight-line slalom, smoothness and proper entry speed
are the keys.
Because the turn radius increases, you should accelerate smoothly through
the slalom, as each turn will get progressively easier. Note that more weight
transfer will occur when you turn to the left, and your car's transient
response will be correspondingly longer, so time your steering inputs
Exercise 3--Braking While Turning (Turn 5)
This exercise is designed to illustrate
that braking and turning simultaneously requires a tradeoff between stopping
ability and cornering ability. You will have to split the friction available to
your tires between slowing your car and changing directions. You control this
split by how much pressure you put on your brake pedal.
When you get to the first pair of pylons, switch from acceleration to
maximum braking and steer the car toward the second set of pylons. Try to come
to a complete stop before reaching the second set. Remember from the slalom
that you must anticipate your car's transient response time by turning slightly
before the first pylons.
Note also that your car's weight will be transferring forward from braking,
as well as to the right from turning. This means that your right-front tire
will be most heavily loaded (generating the most friction), and your left-rear
tire will be most lightly loaded (generating the least). If you detect the rear
tires losing adhesion, reduce your braking pressure; this will transfer weight
back to the rear and increase their adhesion.
Exercise 4--Threshold Braking (Outside Straight)
This exercise gives you a chance to
practice threshold braking. Accelerate briskly down the outside straight toward
Turn 6. When you reach the first of the pylons, begin braking and try to come
to a stop as quickly as possible without locking up your tires or engaging your
ABS. The row of pylons at the edge of the track will serve as a "gauge" of how
quickly you've stopped. The faster you approach the braking pylons, the longer
your braking time will be, giving you more practice time.
The proper technique is to build brake pressure rapidly to a maximum just
shy of locking your tires or activating your ABS. If you overdo it, don't jump
entirely off the pedal. Instead, modulate your pedal pressure by
reducing it just enough to release your tires or stop the ABS activation. With
practice, you'll get a feel for exactly how much foot movement you need.
You will want to concentrate especially on minimizing the transition
time, that is, the time it takes you to switch from acceleration to full
braking. This time directly translates into distance covered, and the faster
you react, the shorter your braking distances will be.
Afternoon On-Track Exercises
In the afternoon, we'll be doing exercises similar to the morning, but we'll
be going clockwise around the track so that the turns will come up in
descending order. We'll begin the session as we did in the morning by dividing
the group and bypassing some of the exercises before starting.
Exercise 5--Obstacle Avoidance (Pit Straight)
In this exercise, you'll simulate
making a last-second maneuver to avoid an obstacle. The track will be divided
into two lanes. Approach the exercise by driving down the center of the track
toward the center pylons. At the last moment, your instructor will either say
"left" or "right" or point to the lane you are to use. Steer into the lane your
instructor indicates and continue through the exercise without braking.
You will have to manage weight transfer and your car's transient response
time. You will also have to look ahead, because if you stare at the
first center pylon, you will not know how much to turn the steering wheel to
enter the designated lane. Instead, focus on the last center pylon and
be prepared to shift your vision to the last pylon on the right or left as
needed. Use your peripheral vision to guide your car into the proper lane.
Try to remain relaxed and alert as you approach the exercise, and try not to
decide which way you're going before your instructor tells you. With each pass,
your instructor will delay his command more. If he fails to tell you which way
to turn, he will expect you to run over the center pylons!
Exercise 6--Lane Change (Turn 6)
As you exit Turn 6, drive between the first pair
of pylons on the left side of the track, and then steer to the right toward the
second pair. As you reach them, steer left to straighten out the car and pass
between them. As you pass through the third pair of pylons, steer left again
toward the fourth pair. Finally, steer to the right while passing between the
fourth pair and exit the exercise. Maintain constant speed through the
exercise, and increase your speed slightly with each successful pass.
Our familiar friends, weight transfer and transient response time, are in
operation here. The key is to allow your car time to settle, i.e.,
restore its balance by redistributing its weight evenly, between the second and
third pair of pylons. If you enter too quickly, your car will still be
unbalanced when you attempt to turn back for the last pair of pylons, and it
will be sluggish in turning (i.e., the transient response time will be longer).
If that happens, do not attempt to force your car through the fourth
set of pylons; if you attempt to slow down, you may transfer enough weight off
the rear tires to spin. Instead, simply abort the exercise by straightening the
steering wheel and driving past the pylons.
Exercise 7--Threshold Braking (Outside Straight)
This exercise is identical to Exercise 4
from the morning, except that you're going in the opposite direction toward
Turn 5. If the exercise is clear when you exit the Lane Change, accelerate past
the unmanned staging point. As you pass the first of the gauge pylons, switch
from acceleration to braking and try to come to a complete stop as quickly as
possible. Use the pylons at the edge of the track to measure your progress.
Exercise 8--Slalom Through a Curve (Turn 4)
Although this is the same setup as Exercise 2, it will prove to be
a lot harder to master. Traveling clockwise, Turn 4 is now a
decreasing-radius turn, and you'll find that you will need a little
more steering input for each pylon. In the morning, you needed to enter
the slalom slowly and accelerate as you traveled through it. Now you'll need to
gradually lose speed as you travel through the slalom, so that the slowest
point is at the last pylon. The same principles of weight transfer and
transient response time are at work here, but they will be magnified as the
turn tightens up sharply near the final pylons.
Before your skidpad session, we'll have you line up on the false grid on the
opposite side than you used when preparing to go out the track. Once
we get the whole group together, a skidpad instructor will lead the group down
to the skidpad. Please be on time for your skidpad sessions, as we
have to hold up the next on-track group until the last car has cleared the
track for the skidpad. If you arrive too late (after the next on-track session
has started), you'll miss your session, as the only access is from the
Our skidpad program is explained in detail in the accompanying Skidpad
Instruction publication. Most students are a bit nervous about their first
skidpad session, but virtually everyone finds them immensely rewarding and
instructive. You have a very rare opportunity; most other BMW CCA chapters
cannot offer skidpad training, and this training directly enhances your ability
to control your car. If you have any questions about the skidpad or our
program, please do not hesitate to ask.
Things to Remember
First and foremost: maintain control of your car at all times. The
best way to learn your car's limits--and the only way we want
you to learn them--is by working up to them. If you drive "over your head,"
you're not going to learn anything, and you're going to endanger yourself and
others in the process.
Second, be aware of what's going on around you. You'll need to
listen to your instructor, but you'll also need to watch out for our course
workers and other drivers. We don't want you running over our workers; they're
hard to replace!
One last thing to remember: the Highway Safety School is supposed to be
fun. It's only natural to be nervous at the start, but as you concentrate
and learn, you'll soon find that adrenaline and exhilaration replace the
butterflies. Pace yourself and enjoy the school!
Revised May 1999