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When out of the water, maintain light pressure on
the brakes for a short distance to heat them up and
dry them out.
Make a test stop when safe to do so. Check
behind to make sure no one is following, then
apply the brakes to be sure they work well. If not,
dry them out further as described above.
(CAUTION: Do not apply too much brake pressure
and accelerator at the same time, or you can
overheat brake drums and linings.
2.14 – Driving in Very Hot Weather
2.14.1 – Vehicle Checks
Do a normal Vehicle inspection, but pay special
attention to the following items.
Tires. Check the tire mounting and air pressure.
Inspect the tires every two hours or every 100 miles
when driving in very hot weather. Air pressure
increases with temperature. Do not let air out or the
pressure will be too low when the tires cool off. If a
tire is too hot to touch, remain stopped until the tire
cools off. Otherwise the tire may blow out or catch
fire.
Engine Oil. The engine oil helps keep the engine
cool, as well as lubricating it. Make sure there is
enough engine oil. If you have an oil temperature
gauge, make sure the temperature is within the
proper range while you are driving.
Engine Coolant. Before starting out, make sure the
engine cooling system has enough water and
antifreeze according to the engine manufacturer's
directions. (Antifreeze helps the engine under hot
conditions as well as cold conditions.) When driving,
check the water temperature or coolant temperature
gauge from time to time. Make sure that it remains
in the normal range. If the gauge goes above the
highest safe temperature, there may be something
wrong that could lead to engine failure and possibly
fire. Stop driving as soon as safely possible and try
to find out what is wrong.
Some vehicles have sight glasses, see-through
coolant overflow containers, or coolant recovery
containers. These permit you to check the coolant
level while the engine is hot. If the container is not
part of the pressurized system, the cap can be
safely removed and coolant added even when the
engine is at operating temperature.
Never remove the radiator cap or any part of the
pressurized system until the system has cooled.
Steam and boiling water can spray under pressure
and cause severe burns. If you can touch the
radiator cap with your bare hand, it is probably cool
enough to open.
If coolant has to be added to a system without a
recovery tank or overflow tank, follow these steps:
Shut engine off.
Wait until engine has cooled.
Protect hands (use gloves or a thick cloth).
Turn radiator cap slowly to the first stop, which
releases the pressure seal.
Step back while pressure is released from cooling
system.
When all pressure has been released, press down
on the cap and turn it further to remove it.
Visually check level of coolant and add more
coolant if necessary.
Replace cap and turn all the way to the closed
position.
Engine Belts. Learn how to check v-belt tightness
on your vehicle by pressing on the belts. Loose belts
will not turn the water pump and/or fan properly.
This will result in overheating. Also, check belts for
cracking or other signs of wear.
Hoses. Make sure coolant hoses are in good
condition. A broken hose while driving can lead to
engine failure and even fire.
2.14.2 – Driving
Watch for Bleeding Tar. Tar in the road pavement
frequently rises to the surface in very hot weather.
Spots where tar "bleeds" to the surface are very
slippery.
Go Slowly Enough to Prevent Overheating. High
speeds create more heat for tires and the engine. In
desert conditions the heat may build up to the point
where it is dangerous. The heat will increase
chances of tire failure or even fire, and engine
failure.
Subsections 2.11, 2.12, 2.13, and 2.14
Test Your Knowledge
1. You should use low beams whenever you can.
True or False?
2. What should you do before you drive if you are
drowsy?
3. What effects can wet brakes cause? How can
you avoid these problems?
4. You should let air out of hot tires so the
pressure goes back to normal. True or False?
5. You can safely remove the radiator cap as long
as the engine isn't overheated. True or False?
Section 2 – Driving Safely Page 2-29
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Commercial Driver’s License Manual – 2005 CDL Testing System
These questions may be on the test. If you can’t
answer all of them, re-read subsections 2.11, 2.12,
2.13, and 2.14.
2.15 – Railroad-highway Crossings
Railroad-highway grade crossings are a special
kind of intersection where the roadway crosses train
tracks. These crossings are always dangerous.
Every such crossing must be approached with the
expectation that a train is coming. It is extremely
difficult to judge the distance of the train from the
crossing as well as the speed of an approaching
train.
2.15.1 – Types of Crossings
Passive Crossings. This type of crossing does not
have any type of traffic control device. The decision
to stop or proceed rests entirely in your hands.
Passive crossings require you to recognize the
crossing, search for any train using the tracks and
decide if there is sufficient clear space to cross
safely.
Active Crossings. This type of crossing has a
traffic control device installed at the crossing to
regulate traffic at the crossing. These active devices
include flashing red lights, with or without bells and
flashing red lights with bells and gates.
2.15.2 – Warning Signs and Devices
Advance Warning Signs. The round, black-on-
yellow warning sign is placed ahead of a public
railroad-highway crossing. The advance warning
sign tells you to slow down, look and listen for the
train, and be prepared to stop at the tracks if a train
is coming. All passenger and hazmat carrying
vehicles are required to stop. See Figure 2.15.
Figure 2.15
Pavement Markings. Pavement markings mean
the same as the advance warning sign. They consist
of an “X” with the letters “”RR” and a no-passing
marking on two-lane roads. See Figure 2.16.
Figure 2.16
There is also a no passing zone sign on two-lane
roads. There may be a white stop line painted on
the pavement before the railroad tracks. The front of
the school bus must remain behind this line while
stopped at the crossing.
Cross-buck Signs. This sign marks the grade
crossing. It requires you to yield the right-of-way to
the train. If there is no white stop line painted on the
pavement, vehicles that are required to stop must
stop no closer than 15 feet or more than 50 feet from
the nearest rail of the nearest track. When the road
crosses over more than one track, a sign below the
cross-buck indicates the number of tracks. See
Figure 2.17.
Figure2.17
Flashing Red Light Signals. At many highway-rail
grade crossings, the cross-buck sign has flashing
red lights and bells. When the lights begin to flash,
stop! A train is approaching. You are required to
yield the right-of-way to the train. If there is more
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than one track, make sure all tracks are clear before
crossing. See Figure 2.18.
Gates. Many railroad-highway crossings have
gates with flashing red lights and bells. Stop when
the lights begin to flash and before the gate lowers
across the road lane. Remain stopped until the
gates go up and the lights have stopped flashing.
Proceed when it is safe. See Figure 2.18.
Figure 2.18
2.15.3 – Driving Procedures
Never Race a Train to a Crossing. Never attempt
to race a train to a crossing. It is extremely difficult
to judge the speed of an approaching train.
Reduce Speed. Speed must be reduced in
accordance with your ability to see approaching
trains in any direction, and speed must be held to a
point which will permit you to stop short of the tracks
in case a stop is necessary.
Don't Expect to Hear a Train. Trains may not or
are prohibited from sounding horns when
approaching some crossings. Public crossings
where trains do not sound horns should be identified
by signs. Noise inside your vehicle may, also
prevent you from hearing the train horn until the train
is dangerously close to the crossing.
Don't Rely on Signals. You should not rely solely
upon the presence of warning signals, gates, or
flagmen to warn of the approach of trains. Be
especially alert at crossings that do not have gates
or flashing red light signals.
Double Tracks Require a Double Check.
Remember that a train on one track may hide a train
on the other track. Look both ways before crossing.
After one train has cleared a crossing, be sure no
other trains are near before starting across the
tracks.
Yard Areas and Grade Crossings in Cities and
Towns. Yard areas and grade crossings in cities
and towns are just as dangerous as rural grade
crossings. Approach them with as much caution.
2.15.4 – Stopping Safely at Railroad- highway
Crossings
A full stop is required at grade crossings whenever:
The nature of the cargo makes a stop mandatory
under state or federal regulations.
Such a stop is otherwise required by law.
When stopping be sure to:
Check for traffic behind you while stopping
gradually. Use a pullout lane, if available.
Turn on your four-way emergency flashers.
2.15.5 – Crossing the Tracks
Railroad crossings with steep approaches can
cause your unit to hang up on the tracks.
Never permit traffic conditions to trap you in a
position where you have to stop on the tracks. Be
sure you can get all the way across the tracks before
you start across. It takes a typical tractor-trailer unit
at least 14 seconds to clear a single track and more
than 15 seconds to clear a double track.
Do not shift gears while crossing railroad tracks.
2.15.6 – Special Situations
Be Aware! These trailers can get stuck on raised
crossings:
Low slung units (lowboy, car carrier, moving van,
possum-belly livestock trailer).
Single-axle tractor pulling a long trailer with its
landing gear set to accommodate a tandem-axle
tractor.
If for any reason you get stuck on the tracks, get out
of the vehicle and away from the tracks. Check
signposts or signal housing at the crossing for
emergency notification information. Call 911 or
other emergency number. Give the location of the
crossing using all identifiable landmarks, especially
the DOT number, if posted.
Section 2 – Driving Safely Page 2-31
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Commercial Driver’s License Manual – 2005 CDL Testing System
2.16 – Mountain Driving
In mountain driving, gravity plays a major role. On
any upgrade, gravity slows you down. The steeper
the grade, the longer the grade, and/or the heavier
the load--the more you will have to use lower gears
to climb hills or mountains. In coming down long,
steep downgrades, gravity causes the speed of your
vehicle to increase. You must select an appropriate
safe speed, then use a low gear, and proper braking
techniques. You should plan ahead and obtain
information about any long, steep grades along your
planned route of travel. If possible, talk to other
drivers who are familiar with the grades to find out
what speeds are safe.
You must go slowly enough so your brakes can hold
you back without getting too hot. If the brakes
become too hot, they may start to "fade." This
means you have to apply them harder and harder to
get the same stopping power. If you continue to use
the brakes hard, they can keep fading until you
cannot slow down or stop at all.
2.16.1 – Select a "Safe" Speed
Your most important consideration is to select a
speed that is not too fast for the:
Total weight of the vehicle and cargo.
Length of the grade.
Steepness of the grade.
Road conditions.
Weather.
If a speed limit is posted, or there is a sign indicating
"Maximum Safe Speed," never exceed the speed
shown. Also, look for and heed warning signs
indicating the length and steepness of the grade.
You must use the braking effect of the engine as the
principal way of controlling your speed. The braking
effect of the engine is greatest when it is near the
governed rpms and the transmission is in the lower
gears. Save your brakes so you will be able to slow
or stop as required by road and traffic conditions.
2.16.2 – Select the Right Gear before Starting
Down the Grade
Shift the transmission to a low gear before starting
down the grade. Do not try to downshift after your
speed has already built up. You will not be able to
shift into a lower gear. You may not even be able to
get back into any gear and all engine braking effect
will be lost. Forcing an automatic transmission into
a lower gear at high speed could damage the
transmission and also lead to loss of all engine
braking effect.
With older trucks, a rule for choosing gears is to use
the same gear going down a hill that you would need
to climb the hill. However, new trucks have low
friction parts and streamlined shapes for fuel
economy. They may also have more powerful
engines. This means they can go up hills in higher
gears and have less friction and air drag to hold
them back going down hills. For that reason, drivers
of modern trucks may have to use lower gears going
down a hill than would be required to go up the hill.
You should know what is right for your vehicle.
2.16.3 – Brake Fading or Failure
Brakes are designed so brake shoes or pads rub
against the brake drum or disks to slow the vehicle.
Braking creates heat, but brakes are designed to
take a lot of heat. However, brakes can fade or fail
from excessive heat caused by using them too
much and not relying on the engine braking effect.
Brake fade is also affected by adjustment. To safely
control a vehicle, every brake must do its share of
the work. Brakes out of adjustment will stop doing
their share before those that are in adjustment. The
other brakes can then overheat and fade, and there
will not be enough braking available to control the
vehicle. Brakes can get out of adjustment quickly,
especially when they are used a lot; also, brake
linings wear faster when they are hot. Therefore,
brake adjustment must be checked frequently.
2.16.4 – Proper Braking Technique
Remember. The use of brakes on a long and/or
steep downgrade is only a supplement to the
braking effect of the engine. Once the vehicle is in
the proper low gear, the following are the proper
braking techniques:
Apply the brakes just hard enough to feel a definite
slowdown.
When your speed has been reduced to
approximately five mph below your "safe" speed,
release the brakes. (This brake application should
last for about three seconds.)
When your speed has increased to your "safe"
speed, repeat steps 1 and 2.
For example, if your "safe" speed is 40 mph, you
would not apply the brakes until your speed reaches
40 mph. You now apply the brakes hard enough to
gradually reduce your speed to 35 mph and then
release the brakes. Repeat this as often as
necessary until you have reached the end of the
downgrade.
Escape ramps have been built on many steep
mountain downgrades. Escape ramps are made to
stop runaway vehicles safely without injuring drivers
and passengers. Escape ramps use a long bed of
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Commercial Driver’s License Manual – 2005 CDL Testing System
loose, soft material to slow a runaway vehicle,
sometimes in combination with an upgrade.
Know escape ramp locations on your route. Signs
show drivers where ramp are located. Escape
ramps save lives, equipment and cargo.
Subsections 2.15 and 2.16
Test Your Knowledge
1. What factors determine your selection of a
"safe" speed when going down a long, steep
downgrade?
2. Why should you be in the proper gear before
starting down a hill?
3. Describe the proper braking technique when
going down a long, steep downgrade.
4. What type of vehicles can get stuck on a
railroad-highway crossing?
5. How long does it take for a typical tractor-trailer
unit to clear a double track?
These questions may be on the test. If you can’t
answer them all, re-read subsections 2.15 and 2.16.
2.17 – Driving Emergencies
Traffic emergencies occur when two vehicles are
about to collide. Vehicle emergencies occur when
tires, brakes, or other critical parts fail. Following the
safety practices in this manual can help prevent
emergencies. But if an emergency does happen,
your chances of avoiding a crash depend upon how
well you take action. Actions you can take are
discussed below.
2.17.1 – Steering to Avoid a Crash
Stopping is not always the safest thing to do in an
emergency. When you don't have enough room to
stop, you may have to steer away from what's
ahead. Remember, you can almost always turn to
miss an obstacle more quickly than you can stop.
(However, top-heavy vehicles and tractors with
multiple trailers may flip over.)
Keep Both Hands on the Steering Wheel. In order
to turn quickly, you must have a firm grip on the
steering wheel with both hands. The best way to
have both hands on the wheel, if there is an
emergency, is to keep them there all the time.
How to Turn Quickly and Safely. A quick turn can
be made safely, if it's done the right way. Here are
some points that safe drivers use:
Do not apply the brake while you are turning. It's
very easy to lock your wheels while turning. If that
happens, you may skid out of control.
Do not turn any more than needed to clear
whatever is in your way. The more sharply you
turn, the greater the chances of a skid or rollover.
Be prepared to "counter-steer," that is, to turn the
wheel back in the other direction, once you've
passed whatever was in your path. Unless you are
prepared to counter-steer, you won't be able to do
it quickly enough. You should think of emergency
steering and counter-steering as two parts of one
driving action.
Where to Steer. If an oncoming driver has drifted
into your lane, a move to your right is best. If that
driver realizes what has happened, the natural
response will be to return to his or her own lane.
If something is blocking your path, the best direction
to steer will depend on the situation.
If you have been using your mirrors, you'll know
which lane is empty and can be safely used.
If the shoulder is clear, going right may be best. No
one is likely to be driving on the shoulder but
someone may be passing you on the left. You will
know if you have been using your mirrors.
If you are blocked on both sides, a move to the
right may be best. At least you won't force anyone
into an opposing traffic lane and a possible head-
on collision.
Leaving the Road. In some emergencies, you may
have to drive off the road. It may be less risky than
facing a collision with another vehicle.
Most shoulders are strong enough to support the
weight of a large vehicle and, therefore, offer an
available escape route. Here are some guidelines,
if you do leave the road.
Avoid Braking. If possible, avoid using the brakes
until your speed has dropped to about 20 mph. Then
brake very gently to avoid skidding on a loose
surface.
Keep One Set of Wheels on the Pavement, if
Possible. This helps to maintain control.
Stay on the Shoulder. If the shoulder is clear, stay
on it until your vehicle has come to a stop. Signal
and check your mirrors before pulling back onto the
road.
Returning to the Road. If you are forced to return
to the road before you can stop, use the following
procedure:
Section 2 – Driving Safely Page 2-33
Version: July 2017
Commercial Driver’s License Manual – 2005 CDL Testing System
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