- A vertical barrier placed directly behind the cab of a tractor to protect the cab in the event cargo should shift forward.
- A vertical barrier across a vehicle to prevent forward movement of cargo.
- A vertical barrier across the front of the deck of a vehicle to prevent forward movement of cargo.
- A transverse load bearing structural component, particularly a part of a log bunk.
Quote From Page 1 Of The CDL Manual:
Headboard:
A vertical barrier across the front of the deck of a vehicle to prevent forward movement of cargo.
- Level ground
- A slight decline
- A slight incline
- Manual slack adjusters can only be checked with the wheels removed
Quote From Page 66 Of The CDL Manual:
Check manual slack adjusters on S-Cam brakes: Park on level ground and chock the wheels to prevent the vehicle from moving. Turn off the parking brakes so you can move the slack adjusters. Use gloves and pull hard on each slack adjuster that you can get to. If a slack adjuster moves more than about one inch where the push rod attaches to it, it probably needs adjusting. Vehicles with too much brake slack can be very hard to stop. Out-of-adjustment brakes are the most common problem found in roadside inspections. Be safe. Check the slack adjusters.
The manual adjustment of automatic slack adjusters is dangerous because it gives the vehicle operator a false sense of security about the effectiveness of the braking system.
TruckingTruth's Advice:
Manual slack adjusters should only be checked while parked on level ground. Be sure to have this memorized as it will come up not only on the written exam, but possibly on your pre-trip exam as well.
- As a partial tier in two groups.
- As a partial tier in one group.
- Any of these are acceptable.
- As a complete tier.
Quote From Page 7 Of The CDL Manual:
Requirements for arranging the top tier

Arrange the top tier as a complete tier, a partial tier in one group, or a partial tier in two groups.
- Doubles/triples are easier to handle in windy conditions than single trailer vehicles
- Doubles/triples are less stable than other commercial vehicles
- Doubles/triples are less prone to rollovers than single trailer vehicles
- Doubles/triples don't jackknife as easily as single trailer vehicles
Quote From Page 80 Of The CDL Manual:
Take special care when pulling two and three trailers. There are more things that can go wrong, and doubles/triples are less stable than other commercial vehicles. Some areas of concern are discussed below.
TruckingTruth's Advice:
Pulling doubles or triples are much more dangerous in nearly every aspect of driving, which is why they require an additional endorsement. Be extra cautious when driving a truck with two or more trailers.
- Hold them behind you
- Carry them under your arm
- Hold them between yourself and the oncoming traffic
- Hold them at your sides
Quote From Page 27 Of The CDL Manual:
When putting out the triangles, hold them between yourself and the oncoming traffic for your own safety (so other drivers can see you).
- On the front and back of the vehicle
- On the rear of the vehicle only
- On the sides of the vehicle
- On both sides and ends of the vehicle
Quote From Page 94 Of The CDL Manual:
Placards must appear on both sides and ends of the vehicle. Each placard must be:
- Easily seen from the direction it faces.
- Placed so the words or numbers are level and read from left to right.
- At least 3 inches away from any other markings.
- Kept clear of attachments or devices such as ladders, doors and tarpaulins.
- Kept clean and undamaged so that the color, format and message are easily seen.
TruckingTruth's Advice:
Make sure you grab an extra placard or two before leaving a shipper in case one of your placards blows away.
- Length and steepness of the grade
- Weather and road conditions
- Speed of vehicles around you
- Total weight of the vehicle and cargo
Quote From Page 30 Of The CDL Manual:
Speed on Downgrades - Your vehicle's speed will increase on downgrades because of gravity. Your most important objective is to select and maintain a speed that is not 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 on downgrades. 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. Shift your transmission to a low gear before starting down the grade and use the proper braking techniques.
- Steering malfunction
- Brake failure
- A tire blows out
- Steep drop-off next to the roadway
Quote From Page 42 Of The CDL Manual:
Vehicle emergencies occur when tires, brakes or other critical parts fail.
TruckingTruth's Advice:
Understand the difference between the following:
- Traffic Hazard: Any road condition or other road user (driver, bicyclist, pedestrian) that is a possible danger.
- Traffic Emergency: When two vehicles are about to collide.
- Vehicle Emergency: When tires, brakes or other critical parts fail.
- Weigh the truck immediately before and after fueling, and do a simple calculation
- Simply go by the number of gallons of fuel each tank holds
- The percentage is standardized amongst manufacturers and is the same for every truck
- Ask another driver what their numbers are
Quote From Page 0 Of The CDL Manual:
- Concrete pipe loaded in a sided vehicle or container.
- Concrete pipe loaded cross-wise on a flatbed trailer.
- Concrete pipe eyes vertical and concrete pipe loaded lengthwise.
- Concrete pipe that is grouped together into a single rigid article and may not roll.
Quote From Page 7 Of The CDL Manual:
What is exempt from these specific requirements?
Follow general cargo securement requirements (Section 2) when transporting the following pipe:
- Concrete pipe that is grouped together into a single rigid article and may not roll.
- Concrete pipe loaded in a sided vehicle or container.
- Concrete pipe eyes vertical and concrete pipe loaded lengthwise.
What is covered under these specific requirements?
Any concrete pipe loaded crosswise on a platform trailer or vehicle that is not exempt.