Texas CVO Knowledge

Texas CVO Knowledge

The Texas Commercial Vehicle Operations (CVO) exam is an important step for obtaining a Commercial Driver's License (CDL) in the state of Texas. This exam assesses the candidate's knowledge of safety and regulations related to operating commercial vehicles. The exam includes both theoretical questions and a practical driving test.

These questions will help you better understand the format of the exam and prepare for it as effectively as possible. Practical questions are located further down on this page.

Color of clearance lamps on front of a vehicle
Amber
The load on a vehicle may not extend beyond the front of the vehicles, without a special permit, more than:
Three feet
Trailer and semitrailers must ordinarily have brakes that can be applied by the driver when the gross weight of the trailer exceeds:
4,500 pounds
The load on a truck may not extend over the rear of the vehicle more than:
four feet
All trailers or semitrailers must be equipped with clearance lamps, side marker lamps, and side reflectors if their width is:
80 inches or more
To find out the details about registering your particular vehicle, you should consult:
County Tax-Assessor Collector
When one truck is following another truck or vehicle, it may keep far enough back to allow how many vehicles to enter safely between them?
One vehicle
Turn signal indicators are required on all motor vehicles manufactured after model year?
1959
No combination of vehicles, other than a truck tractor-trailer combination, may exceed:
65 feet
Vehicles transporting loose materials (sand, dirt, gravel, etc.) that is capable of spilling or blowing from the vehicle must:
Meet loading and/or covering regulations to prevent spilling or blowing.
Every farm tractor and every self-propelled unit of farm equipment or implement of husbandry manufactured or assembled after January 1, 1972, complies with state lighting laws by:
Having two headlamps
The maximum speed limit for a taxicab on numbered U.S. or state highways in the daytime is:
70 mph
To operate on the highway a motor vehicle or trailer having metal, tires and weighing 5,000 pounds or more, you must:
Get a special permit from the Texas Department of Transportation.
During the times when lighted lamps are not required, the driver should set out:
two approved red flags
Before going down a steep grade with a commercial vehicle, you should:
Shift to a lower gear.
Every trailer must have how many reflectors on the rear?
Two
No passenger vehicle may be coupled with more than:
One trailer
When is it necessary to place flares around a truck on a two-way road with a clear view, one must be placed beside the truck, the other two must be placed:
100 feet to the front and rear of the truck
All school buses, buses, taxis, and other vehicles hauling passengers for hire or lease must carry a chemical type fire extinguisher of at least:
One quart capacity.
When a load extends more than four feet over the rear of a vehicle, what color flag must be attached to the extreme end of the extension while driving in the daytime?
Red.
Which of the following motor vehicles must stop at all railroad grade crossings outside a business or residential district?
Motor bus.
The maximum number of trailers that may be lawfully towed by one vehicle is:
Two
The maximum number of trailers that may be towed by a commercial motor vehicle with an unloaded weight in excess of 2,500 pounds is:
Two trailers.
To haul a load or more equipment that is wider, heavier, or longer than the law permits, you must:
Obtain a permit from the Texas Department of Transportation
Clearance lights are required by state law for trucks or buses if the width is:
80 inches or more
When towing another vehicle with a chain, rope, or cable, what color flag must be attached to the chain, rope, or cable?
White
It is unlawful to operate a motor vehicle on a highway with:
Flanges or lugs on the wheels.
One purpose of requiring registration papers on trucks at all times is to show:
The weight of the truck empty and how much it is registered to haul.
The top speed limit for heavy trucks on designated rural interstate in the nighttime is:
65 mph
When going downhill with a commercial vehicle, it is unlawful to:
Coast.
Which of the following vehicles are not required to have mud flaps?
Pole trailers.
What is the maximum speed limit for a taxicab on a numbered U.S. or state highway during the day?
70 mph
A slowing moving vehicle emblem must be displayed only by:
Vehicles designed to be operated at speeds of 25 mph or less.
The first thing the driver of a disabled truck or bus should do is:
Set out flares, reflectors, or flags.
The length requirements of state law for vehicles or combinations of vehicles, including extensions over the front and rear, do not apply:
Within city limits.
The height from the ground for mounting reflectors must be at least:
24 inches
When turning with a long vehicle or combination truck-trailer, if it is impossible to stay in the proper lane, you should:
Approach the corner about 4 feet from the curb or right edge of the roadway, then if necessary, complete the turn in the center of the street entered.
Clearence lamps mounted on the rear or on the side near the rear of a vehicle must be what color?
Red.
When stopped on the side of a divided highway, flags or reflectors must be placed:
One 10 feet behind the vehicle, one 100 feet behind, and one 200 feet behind the vehicles.
The maximum speed limit for a pickup truck with a manufacturer's rated carrying capacity of 2,000 lbs or less on U.S. or state highway in the daytime is:
70 mph
When backing a large truck you should:
Have someone guide you.
The greatest weight allowed by state law for any vehicle including its load is:
80,000 pounds
The greatest height ordinarily allowed by state law for a vehicle including its load is:
14 feet
The greatest width allowed by State law for a truck including its load is:
102 inches or 8 1/2 ft
The greatest length allowed by State law for a single motor vehicle other than a truck tractor is:
45 feet
One purpose of requiring registration papers on trucks at all times is to show:
Weight of the truck empty and how much it is registered to haul.
To operate on the highway a motor vehicle or trailer having metal tires and weighting 5,000 lbs or more must have:
A special permit from the Department of Transportation.
To prevent damage to the highway it is unlawful to operate any motor vehicle with:
Studs or spikes on the wheels.
Air brake systems combine what three different systems?
Service brakes, parking brakes, and emergency brakes.
When should you drain the air tanks?
After every working day.
Why drain water from the compressed air tanks?
Water can freeze in cold weather and cause brake failure.
Air brake-equipped vehicles must have:
A supply pressure gauge and a warning signal when psi drops below 60.
What can legally hold a parking or emergency brake in position for a truck, truck tractor, or bus?
Spring pressure.
The first thing you should do when the low air pressure warning comes on?
Stop and safely park ASAP.
The braking power of the spring brakes:
Depends on the adjustment of the service brakes.
The application pressure gauge shows the driver how much pressure:
Is being applied to the brakes.
Which type of brake is the most common in commercial vehicles?
S-cam brake
An application pressure gauge...
Shows how much air pressure you are applying to the brakes.
To test service brakes you should...
Release the parking brake, move forward slowly, and depress the brakes.
Air brakes take longer to stop than hydraulic brakes because...
It takes longer for the air to flow through the lines.
The proper way to go down long grades is to...
Apply brakes just hard enough to reduce speed to 5 mph below safe speed, then release until back to safe speed and repeat the process.
When should you avoid using the parking brake?
When the brakes are hot.
If your vehicle has an alcohol evaporator, everyday during cold weather you should:
Check and fill the alcohol level.
During normal driving, spring brakes are usually held back by what?
Air pressure
In air brake vehicles, the parking brakes should be used when?
Whenever the vehicle is parked.
The brake pedal in an air brake system does what?
Controls the air pressure applied to put on the brakes.
A straight truck or bus air brake system should not leak at a rate of more than ____ PSI per minute with the engine off and the brakes released.
2
An alcohol evaporator does what?
Reduces the risk of ice in the air brake valves in cold weather.
Air loss should not be more than ___ with the engine off and brakes released.
2 psi per minute
How do you know when your brakes are fading?
You have to push harder on the brake pedal to control your speed on a downgrade.
To check the free play of manual slack adjusters on S-cam brakes you should:
Park on a level ground, chock wheels, and release parking brake.
When driving down a long steep hill you should:
Release the brake when you are 5 mph below your safe speed.
The most common type of foundation brakes found on heavy vehicles is the:
S-cam drum
Air brakes should be drained...
1. At the end of each working day. 2. To keep sludge from clogging system valves. 3. Manually when automatic devices fail.
The governor allows the air to start pumping again when it reaches the cut-in level or around...
100 psi
You should not use the parking brakes...
When the brakes are hot.
The air compressor governor controls...
When the air compressor pumps air into the storage tanks.
A dual air brake system...
Has two brake systems and one set of controls.
An emergency brake...
Is required on commercial vehicles, must be held by mechanical force, could be activated by loss of air pressure.
With dual air systems, the air pressure should build...
From 85 to 100 psi in 45 seconds
A fully charged air system typically has ____ psi.
125
To test air leakage rate you should...
Turn off engine and release the service brake.
When testing air leakage rates for combination vehicles (before applying the brake pedal), air brake systems should not lose air faster than...
3 psi per minute.