Page 25 - 2021-2022 Commercial Drivers Manual

SECTION 2 : DRIVING SAFETY

TEST YOUR KNOWLEDGE 6 seconds. Over 40 mph, you’d need 5 seconds
for a 40-foot vehicle and 7 seconds for a 60-foot
Subsections 2.4, 2.5 and 2.6 vehicle. See Figure 2.12.
To know how much space you have, wait
• How far ahead does the manual say you • What three things add up to total until the vehicle ahead passes a shadow on the
should look? stopping distance? road, a pavement marking, or some other clear
landmark. Then count off the seconds like this:
• What are two main things to look for • If you go twice as fast, will your stopping “one thousand- and-one, one thousand-and-
ahead? distance increase by two or four times? two” and so on, until you reach the same spot.
• What’s your most important way to see • Empty trucks have the best braking. True Compare your count with the rule of one second
the sides and rear of your vehicle? or False? for every ten feet of length.
If you are driving a 40-foot truck and only
• What does “communicating” mean in • What is hydroplaning? counted up to 2 seconds, you’re too close. Drop
safe driving?
• What is “black ice”? back a little and count again until you have 4
• Where should your reflectors be placed seconds of following distance (or 5 seconds, if
when stopped on a divided highway? you’re going over 40 mph). After a little practice,
you will know how far back you should be.
These questions may be on the test. If you can’t answer them all, re-read subsections 2.4, Remember to add 1 second for speeds above

2.5, and 2.6. 40 mph. Also remember that when the road is
slippery, you need much more space to stop.
2.7.2 – Space Behind
2.6.5 – Speed and Traffic Flow section on going down long, steep downgrades You can’t stop others from following you too
safely in “Mountain Driving.” closely. But there are things you can do to make
When you’re driving in heavy traffic, the saf- it safer.
est speed is the speed of other vehicles. Vehicles 2.6.7 – Roadway Work Zones
going the same direction at the same speed Stay to the Right. Heavy vehicles are often
are not likely to run into one another. In many Speeding traffic is the number one cause tailgated when they can’t keep up with the

states, speed limits are lower for trucks and of injury and death in roadway work zones. speed of traffic. This often happens when you’re

buses than for cars. It can vary as much as 15 Observe the posted speed limits at all times going uphill. If a heavy load is slowing you
mph. Use extra caution when you change lanes when approaching and driving through a work down, stay in the right lane if you can. Going

or pass on these roadways. Drive at the speed of zone. Watch your speedometer, and don’t allow uphill, you should not pass another slow vehicle
the traffic, if you can without going at an illegal your speed to creep up as you drive through unless you can get around quickly and safely.

or unsafe speed. Keep a safe following distance. long sections of road construction. Decrease Dealing with Tailgaters Safely. In a large
The main reason drivers exceed speed limits your speed for adverse weather or road condi- vehicle, it’s often hard to see whether a vehicle
is to save time. But, anyone trying to drive faster tions. Decrease your speed even further when is close behind you. You may be tailgated:
than the speed of traffic will not be able to save a worker is close to the roadway.
much time. The risks involved are not worth it. • When you are traveling slowly. Drivers
If you go faster than the speed of other traffic, 2.7 – Managing Space trapped behind slow vehicles often follow
you’ll have to keep passing other vehicles. This closely.
increases the chance of a crash, and it is more To be a safe driver, you need space all around
tiring. Fatigue increases the chance of a crash. your vehicle. When things go wrong, space
Going with the flow of traffic is safer and easier.
gives you time to think and to take action.
To have space available when something goes
2.6.6 – Speed on Downgrades HEAVY VEHICLE FORMULA
wrong, you need to manage space. While this is For timed interval following distance
Your vehicle’s speed will increase on down- true for all drivers, it is very important for large
grades because of gravity. Your most important vehicles. They take up more space and they
objective is to select and maintain a speed that require more space for stopping and turning.
is not too fast for the:
2.7.1 – Space Ahead
• Total weight of the vehicle and cargo.
Of all the space around your vehicle, it is

• Length of the grade.
the area ahead of the vehicle--the space you’re
• Steepness of the grade. driving into --that is most important.
• Road conditions. The Need for Space Ahead. You need space
ahead in case you must suddenly stop. Accord-
• Weather.
ing to accident reports, the vehicle that trucks
If a speed limit is posted, or there is a sign in- and buses most often run into is the one in front
dicating “Maximum Safe Speed,” never exceed of them. The most frequent cause is following
the speed shown. Also, look for and heed warn- too closely. Remember, if the vehicle ahead of
ing signs indicating the length and steepness of you is smaller than yours, it can probably stop
the grade. You must use the braking effect of the faster than you can. You may crash if you are
engine as the principal way of controlling your following too closely.
speed on downgrades. The braking effect of the
engine is greatest when it is near the governed How Much Space? How much space should
rpms and the transmission is in the lower gears. you keep in front of you? One good rule says
Save your brakes so you will be able to slow or you need at least one second for each 10 feet of
stop as required by road and traffic conditions. vehicle length at speeds below 40 mph. At great-
Shift your transmission to a low gear before er speeds, you must add 1 second for safety. For
starting down the grade and use the proper example, if you are driving a 40-foot vehicle,
braking techniques. Please read carefully the you should leave 4 seconds between you and
the vehicle ahead. In a 60-foot rig, you’ll need Figure 2.12
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