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OR CDL School Bus practice questions

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Question 1Driving Safely

Before driving a school bus, you must complete a pre-trip inspection. What is the main purpose of this inspection?

  1. To confirm the bus is mechanically safe and all required equipment works Correct answer.
  2. To check that students have boarded the correct bus
  3. To verify the driver's route schedule for the week
  4. To record the number of students riding that day

Explanation

The pre-trip inspection is a safety check performed before every trip to confirm brakes, lights, tires, mirrors, emergency equipment, and other required items are in working order. It is not an administrative or route-planning task, and it must be done by the driver before moving the vehicle.

Question 2Driving Safely

When a school bus is stopped to load or unload students, which warning device must be operating to alert approaching traffic?

  1. The backup alarm
  2. The red flashing lights and stop arm Correct answer.
  3. The high-beam headlights
  4. The four-way hazard flashers only

Explanation

A school bus loading or unloading students must activate its red flashing warning lights and extend the stop arm so traffic in both directions knows to stop. These signals are legally required and are distinct from ordinary hazard flashers.

Question 3Driving Safely

How far before a railroad crossing must a school bus stop when the crossing has no gates or a driver is required to stop?

  1. 75 to 100 feet
  2. 150 to 200 feet
  3. 5 to 10 feet
  4. 15 to 50 feet Correct answer.

Explanation

A school bus must stop 15 to 50 feet before the nearest rail at a railroad crossing. This distance keeps the bus clear of the tracks while giving the driver a view of approaching trains. Stopping too close risks being struck; stopping too far back reduces visibility.

Question 4Driving Safely

A school bus is approaching a blind curve on a narrow rural road. What is the safest action?

  1. Move to the left lane to improve the view around the curve
  2. Maintain speed and stay in the center of the road
  3. Slow down and keep well to the right side of the lane Correct answer.
  4. Sound the horn continuously through the curve

Explanation

On a blind curve the driver cannot see oncoming traffic, so reducing speed and staying to the right gives more room and reaction time if another vehicle appears. Crossing into the left lane or holding speed in the center increases the risk of a head-on collision.

Question 5Driving Safely

When must a school bus driver use the four-way hazard flashers while driving?

  1. Whenever the bus is stopped to load students
  2. When approaching a railroad crossing
  3. When the bus is disabled or moving unusually slowly Correct answer.
  4. When turning left at an intersection

Explanation

Hazard flashers warn other drivers that the bus is a temporary hazard, such as when it is broken down or creeping along at an unsafe slow speed. They are not used for normal loading stops, which rely on the red lights and stop arm.

Question 6Driving Safely

A school bus driver must stop for a railroad crossing. What should the driver do before crossing the tracks?

  1. Rely on the crossing gate to protect the bus
  2. Look and listen in both directions and confirm the tracks are clear Correct answer.
  3. Open the door and listen, then proceed without stopping again
  4. Turn off the engine to hear better

Explanation

At a railroad crossing the driver must stop, then look and listen carefully in both directions to confirm no train is approaching before proceeding. Opening the door or window helps the driver hear, but the engine should stay running and gates are not a substitute for the driver's own observation.

Question 7Driving Safely

What is the proper way to hold the steering wheel for maximum control of a school bus?

  1. One hand at the top of the wheel
  2. Both hands gripping the inside of the wheel
  3. Both hands on the outside of the wheel, at roughly the 9 and 3 o'clock positions Correct answer.
  4. One hand on the wheel and one on the gear shift at all times

Explanation

Holding the wheel with both hands on the outside at about 9 and 3 o'clock gives the best control and keeps the arms clear of the air bag. Gripping the inside of the wheel or driving one-handed reduces control, especially during sudden maneuvers.

Question 8Driving Safely

A school bus with air brakes has been sitting overnight. What should the driver check during the pre-trip inspection?

  1. That the air pressure builds and holds, and that the low-pressure warning works Correct answer.
  2. That the parking brake is disconnected
  3. That the air tanks are completely empty
  4. That the brake pedal feels soft

Explanation

An air-brake pre-trip check confirms the compressor builds pressure to the proper level, the system holds pressure without excessive leakage, and the low-pressure warning activates. Empty tanks, a disconnected parking brake, or a soft pedal all indicate problems rather than proper function.

Question 9Driving Safely

While driving at highway speed, a school bus driver notices the bus is drifting to the right. What is the safest first response?

  1. Brake hard immediately
  2. Ease off the accelerator and steer gently back into the lane Correct answer.
  3. Accelerate to regain control
  4. Jerk the wheel sharply to the left

Explanation

Gentle correction with a smooth steering input and a reduction in speed is the safest way to counter drift. Hard braking, sharp steering, or accelerating can cause a loss of control or a skid, especially with a heavy vehicle.

Question 10Driving Safely

What is the correct following distance for a school bus traveling at highway speeds in good conditions?

  1. One second behind the vehicle ahead
  2. Two car lengths behind the vehicle ahead
  3. As close as needed to keep other traffic from cutting in
  4. At least four seconds behind the vehicle ahead Correct answer.

Explanation

A school bus needs a following distance of at least four seconds in good conditions because of its size and stopping distance. One second or a couple of car lengths is far too close for a heavy vehicle, and tailgating to block cut-ins is unsafe.

Question 11Driving Safely

A school bus must back up during a route. What is the safest practice?

  1. Sound the horn and back without checking
  2. Rely only on the mirrors
  3. Back quickly to minimize time spent in reverse
  4. Use a spotter and back slowly only when necessary Correct answer.

Explanation

Backing a school bus is inherently risky, so it should be avoided whenever possible and done slowly with a spotter outside the bus when one is available. The driver must also use mirrors and check the area behind the bus before moving.

Question 12Driving Safely

When a school bus is involved in loading students at a stop, when should the driver check the mirrors?

  1. Continuously while students load and until the door is closed Correct answer.
  2. Only before opening the door
  3. Only when students are out of sight
  4. Only after pulling away from the stop

Explanation

The driver must monitor the mirrors continuously during loading and unloading to watch for students near the bus, approaching traffic, and anyone in the danger zone. Checking only at the start or after departure leaves long periods unmonitored.

Question 13Driving Safely

How should a school bus driver handle a student who is standing in the aisle while the bus is moving?

  1. Ask another student to pull the student into a seat
  2. Continue driving and address it at the next stop
  3. Speed up to reach the school sooner
  4. Stop the bus in a safe place and require the student to be seated Correct answer.

Explanation

Students must remain seated while the bus is moving, so the driver should pull over safely and require the student to sit down before continuing. Continuing to drive or speeding up leaves the student at risk of injury in a sudden stop.

Question 14Driving Safely

A school bus is stopped on a hill facing downhill. How should the driver set the parking brake before leaving the bus?

  1. Release the parking brake and rely on the transmission
  2. Set the parking brake and turn the wheels away from the curb
  3. Set the parking brake and turn the wheels toward the curb Correct answer.
  4. Leave the engine running in gear

Explanation

On a downhill grade the parking brake should be set and the front wheels turned toward the curb so the bus would roll into the curb rather than into traffic if it moved. Leaving the bus in gear without the brake or with the wheels turned the wrong way is unsafe.

Question 15Driving Safely

What does the danger zone around a school bus refer to?

  1. The area behind the bus beyond ten feet
  2. The area around the bus where students are at greatest risk of being hit Correct answer.
  3. The area directly in front of the bus only
  4. The lane to the left of the bus

Explanation

The danger zone is the area all around the school bus, especially close to the front, sides, and rear, where students are hardest for the driver to see and most at risk. It is not limited to one side or a single direction.

Question 16Driving Safely

A school bus driver is driving in fog. Which lights should be used?

  1. Four-way hazard flashers while moving at full speed
  2. Parking lights only
  3. Low-beam headlights Correct answer.
  4. High-beam headlights

Explanation

Low-beam headlights are correct in fog because high beams reflect off the moisture and reduce visibility. Parking lights alone are too dim, and hazard flashers are reserved for a disabled or unusually slow vehicle, not normal fog driving.

Question 17Driving Safely

What should a school bus driver do if the bus starts to skid on an icy road?

  1. Brake hard and steer sharply
  2. Turn the wheel opposite to the direction of the skid
  3. Ease off the accelerator and steer in the direction the bus should go Correct answer.
  4. Accelerate to pull out of the skid

Explanation

In a skid the driver should ease off the accelerator and steer smoothly in the direction the bus should travel, allowing the tires to regain traction. Hard braking, accelerating, or steering against the skid can make the slide worse.

Question 18Driving Safely

A school bus is approaching an intersection with a flashing yellow traffic signal. What does this signal mean?

  1. Stop only if students are present
  2. Yield only to buses
  3. Stop and wait for a green light
  4. Proceed with caution Correct answer.

Explanation

A flashing yellow signal means the driver may proceed but must slow down and use caution, watching for cross traffic and pedestrians. It does not require a full stop the way a red signal does.

Question 19Driving Safely

When a school bus is stopped to unload students and a student must cross the road, what should the driver do?

  1. Have the student cross behind the bus
  2. Wait until traffic has stopped in both directions and then signal the student to cross Correct answer.
  3. Signal the student to cross immediately
  4. Honk to warn traffic and let the student cross alone

Explanation

The driver must confirm that traffic in both directions has stopped before signaling a student to cross in front of the bus. Signaling too soon or letting the student cross behind the bus exposes the student to moving traffic.

Question 20Driving Safely

What is the purpose of the school bus driver's mirror check before moving away from a loading stop?

  1. To verify the route schedule
  2. To check the bus's fuel level
  3. To confirm students are clear of the bus and no one is in the danger zone Correct answer.
  4. To adjust the radio volume

Explanation

Before pulling away, the driver checks the mirrors to confirm all students are clear of the bus and no one remains in the danger zone. This final check prevents a student from being struck by the moving bus.

Question 21Driving Safely

A school bus driver must drive through a work zone with narrowed lanes. What is the safest approach?

  1. Reduce speed, increase following distance, and watch for workers and equipment Correct answer.
  2. Use the shoulder to pass slower traffic
  3. Maintain the posted speed and stay close to the vehicle ahead
  4. Sound the horn to clear the zone

Explanation

In a work zone the driver should slow down, leave extra following distance, and stay alert for workers, equipment, and changing lane patterns. Maintaining speed or using the shoulder increases the risk of a collision.

Question 22Driving Safely

When a school bus is being operated at night, what should the driver do when meeting an oncoming vehicle?

  1. Keep the high beams on to see better
  2. Dim the headlights to low beam Correct answer.
  3. Flash the high beams repeatedly
  4. Turn on the interior lights

Explanation

When meeting oncoming traffic at night, the driver should switch from high beams to low beams so the other driver is not blinded. Keeping high beams on or flashing them can dazzle the oncoming driver and cause a crash.

Question 23Driving Safely

A school bus driver is transporting students and the bus's antilock braking system (ABS) warning light comes on. What should the driver do?

  1. Pump the brakes to reset the light
  2. Ignore it because ABS is not important
  3. Continue to the destination and report the fault for repair Correct answer.
  4. Immediately stop in the travel lane

Explanation

An ABS warning light indicates a fault that should be reported and repaired, but the bus still has conventional brakes, so the driver can continue carefully to a safe destination and document the issue. Stopping in a travel lane would create a new hazard.

Question 24Driving Safely

What should a school bus driver do when a student's parent signals the bus to stop between designated stops?

  1. Stop in the traffic lane and open the door
  2. Continue to the designated stop and follow district policy Correct answer.
  3. Back up to pick up the student
  4. Stop wherever the parent is standing

Explanation

School buses load and unload only at designated stops under district policy, so the driver should continue to the assigned stop rather than stopping in an unsafe location. Stopping in a traffic lane or backing up creates serious hazards.

Question 25Driving Safely

Why should a school bus driver avoid sudden lane changes on a multi-lane highway?

  1. The bus is large with blind spots, and other drivers may not see it or expect the move Correct answer.
  2. The bus's turn signals do not work at highway speed
  3. Lane changes are prohibited for school buses
  4. Other drivers always have the right of way

Explanation

A school bus is large and has significant blind spots, so a sudden lane change can surprise drivers in the adjacent lane who may not see the bus. Signaling early, checking mirrors, and changing lanes smoothly reduce that risk.

Question 26Driving Safely

Before a school bus driver moves the bus away from a curb after loading students, what is the proper sequence of actions?

  1. Signal, check mirrors and blind spots, then accelerate smoothly while checking the left mirror Correct answer.
  2. Turn on the hazard lights, wave students back, and accelerate while checking the crossing mirror
  3. Check the left mirror only, release the brake, and pull out quickly to keep traffic moving
  4. Sound the horn, release the parking brake, and pull out while watching the right mirror

Explanation

A school bus leaves a stop only after signaling, confirming the area around the bus is clear through mirrors and a blind-spot check, and then accelerating gradually so standing or seated students are not thrown off balance. Pulling out before the blind-spot check risks striking a pedestrian or vehicle hidden alongside the bus.

Question 27Driving Safely

How should a school bus driver adjust speed when driving on a gravel or unpaved route road?

  1. Reduce speed below the posted limit to keep traction and control Correct answer.
  2. Speed up to get off the loose surface quickly
  3. Maintain the posted speed so the schedule is kept
  4. Keep the same speed but use cruise control for steadiness

Explanation

Loose gravel reduces tire grip and lengthens stopping distance, so the driver should travel slower than the posted limit and avoid abrupt steering or braking. The posted limit assumes good surface conditions and does not guarantee safe traction on unpaved roads.

Question 28Driving Safely

A school bus driver approaching a curve on a rural route should manage speed in what way?

  1. Brake firmly while inside the curve to hold the lane
  2. Enter the curve at the posted speed and brake as needed in the curve
  3. Slow down before entering the curve, then accelerate gently through it Correct answer.
  4. Shift to neutral and coast around the curve

Explanation

Speed should be reduced before the curve so the bus is already at a safe pace on entry; gentle acceleration through the curve helps maintain stability. Braking hard while turning can cause a skid or loss of control, especially with a high center of gravity.

Question 29Driving Safely

What is the primary reason a school bus driver should keep both hands on the wheel and avoid distractions while students are aboard?

  1. It makes the ride quieter for the students
  2. It is required only when a monitor is not present
  3. It preserves reaction time for sudden hazards around a heavy vehicle Correct answer.
  4. It shortens the route time

Explanation

A loaded school bus is heavy and needs more distance and time to stop, so any distraction that takes hands or eyes away delays the driver's response to a child, vehicle, or hazard. Quiet rides and schedule gains are not safety justifications.

Question 30Driving Safely

A school bus driver is driving in heavy rain and the roadway has standing water. What is the safest action?

  1. Apply the brakes firmly to dry the brakes immediately
  2. Accelerate through the water to keep momentum
  3. Move to the left lane to avoid the deepest water
  4. Slow down and, if steering feels light, ease off the accelerator without braking hard Correct answer.

Explanation

Standing water can cause hydroplaning, in which the tires lose contact with the road and steering feels light. The correct response is to reduce speed and ease off the accelerator gently until traction returns; hard braking or acceleration can worsen the loss of control.

Question 31Driving Safely

When a school bus driver must cross a bridge that is posted with a weight limit lower than the loaded bus weight, what should the driver do?

  1. Cross in a lower gear to spread the load
  2. Cross slowly to reduce the load on the bridge
  3. Do not cross and report the situation to the dispatcher for an alternate route Correct answer.
  4. Cross only if no other vehicles are on the bridge

Explanation

A posted weight limit is a legal and structural restriction; a bus that exceeds it must not cross regardless of speed, gear, or traffic. The driver should stop and contact dispatch to arrange a safe alternate route.

Question 32Driving Safely

What does a school bus driver do when approaching a drawbridge that is in the process of opening?

  1. Stop at a safe distance and wait until the bridge is fully closed and the signal permits crossing Correct answer.
  2. Proceed quickly before the span rises further
  3. Sound the horn and continue at reduced speed
  4. Stop on the bridge approach and turn on the hazard lights only

Explanation

An opening drawbridge is an active hazard; the driver must stop well back from the barrier and warning signals and cross only after the span is fully closed and the signal allows movement. Trying to beat the span risks a catastrophic fall.

Question 33Driving Safely

A school bus driver notices the bus pulling to one side after a tire blowout at highway speed. What is the correct response?

  1. Accelerate to stabilize the bus and then pull over
  2. Hold the wheel firmly, ease off the accelerator, and let the bus slow before braking gently Correct answer.
  3. Turn the wheel sharply toward the shoulder to leave the lane quickly
  4. Brake hard immediately and steer for the shoulder

Explanation

After a blowout the driver should grip the wheel firmly to counter the pull, release the accelerator so the bus slows gradually, and brake only gently once control is regained. Hard braking or sharp steering can cause a rollover, particularly in a high-profile school bus.

Question 34Driving Safely

When a school bus driver is driving at night on an unlit rural road, what following-distance practice is appropriate?

  1. Increase the following distance beyond the daytime gap Correct answer.
  2. Turn on high beams continuously and follow closely
  3. Follow closer so the lead vehicle's taillights guide the way
  4. Use the same following distance as in daylight

Explanation

At night the driver can see only as far as the headlights illuminate, so stopping distance effectively grows and the following gap should be increased beyond the daytime distance. Following closer reduces the time available to react to hazards that appear suddenly in the beam.

Question 35Driving Safely

What should a school bus driver do if the bus's brakes feel spongy or the pedal sinks toward the floor while driving with students aboard?

  1. Pull over safely, stop the bus, and do not continue until the brake problem is resolved Correct answer.
  2. Pump the brakes repeatedly and continue the route
  3. Shift to a lower gear and continue at reduced speed
  4. Continue normally and report the issue at the end of the route

Explanation

A spongy or sinking brake pedal signals a possible loss of hydraulic pressure, which could lead to complete brake failure. The driver must stop in a safe location, keep students aboard safely, and not resume the route until the fault is corrected and the bus is cleared.

Question 36Driving Safely

When a school bus driver must drive through a tunnel, which practice supports safe operation?

  1. Remove sunglasses and rely on the tunnel lighting only
  2. Speed up to exit the tunnel sooner
  3. Turn on the hazard lights for the entire tunnel length
  4. Turn on the headlights and keep a steady speed with extra following distance Correct answer.

Explanation

Headlights improve the driver's visibility and make the bus visible to others in the dim tunnel, and extra following distance compensates for the sudden change in lighting. Speeding or relying only on tunnel lighting reduces the margin for hazards ahead.

Question 37Driving Safely

A school bus driver is on a route when a fire truck with siren and flashing lights approaches from behind. What should the driver do?

  1. Pull to the right edge of the roadway and stop until the emergency vehicle passes Correct answer.
  2. Speed up to reach the next stop before the fire truck passes
  3. Continue at the same speed and ignore the emergency vehicle
  4. Stop immediately in the travel lane

Explanation

The driver should yield by pulling as far right as is safe and stopping until the emergency vehicle has passed, while keeping students calm and seated. Stopping in the travel lane blocks the emergency vehicle and creates a collision hazard.

Question 38Driving Safely

What is the safest way for a school bus driver to handle a railroad crossing where the gates are down but no train is visible?

  1. Wait until the gates rise and the signal permits crossing Correct answer.
  2. Have a passenger flag the bus across the tracks
  3. Proceed slowly through the gate if the bus is behind schedule
  4. Drive around the gate after checking both directions

Explanation

A lowered gate means the crossing protection is active and a train may be approaching even if none is visible. The driver must wait until the gates rise and the signals allow crossing; driving around a gate is illegal and can be fatal.

Question 39Driving Safely

Why should a school bus driver avoid using the brakes while steering hard to avoid a hazard?

  1. Braking while turning is only a problem on wet roads
  2. Braking while turning improves the turning radius
  3. Braking while turning makes the bus quieter
  4. Braking while turning reduces the traction available for steering and can cause a skid Correct answer.

Explanation

Tires have limited traction, and asking them to brake and steer at the same time divides that traction between the two tasks. On a heavy, high-center-of-gravity school bus this can lead to a skid or rollover, so the driver should separate braking from hard steering whenever possible.

Question 40Driving Safely

What should a school bus driver do when the route requires driving through a low underpass marked with a clearance lower than the bus height?

  1. Drive through after checking that no other vehicles are present
  2. Proceed slowly and watch the roofline in the mirror
  3. Let air out of the tires to lower the bus
  4. Do not enter and find an alternate route that clears the bus height Correct answer.

Explanation

A posted clearance lower than the bus height means the bus cannot pass safely, and the driver must choose another route. Attempting the underpass risks striking the bridge structure, which can injure students and damage the bus.

Question 41Transporting Passengers Safely

Before a school bus driver may transport passengers, which of the following must be completed for the bus itself?

  1. A commercial vehicle registration renewal
  2. A quarterly engine tune-up
  3. A fuel efficiency test
  4. A pre-trip inspection of the bus Correct answer.

Explanation

The driver must inspect the bus before each trip to confirm lights, brakes, tires, mirrors, and emergency equipment are working. This pre-trip inspection is the driver's responsibility and is required before transporting any passengers.

Question 42Transporting Passengers Safely

When a school bus driver stops to load or unload students, the driver should first:

  1. Check mirrors and activate the warning lights and stop arm Correct answer.
  2. Open the door and let students exit immediately
  3. Turn off the engine to save fuel
  4. Radio dispatch for permission

Explanation

Before students load or unload, the driver must check all mirrors for traffic and activate the flashing warning lights and stop arm to alert other motorists. Only after confirming it is safe should the door be opened.

Question 43Transporting Passengers Safely

When students must cross the road after exiting the school bus, the driver should:

  1. Allow them to cross wherever they choose
  2. Signal them to cross behind the bus
  3. Honk to alert traffic and let them cross alone
  4. Signal them to cross in front of the bus after they walk to the edge of the roadway Correct answer.

Explanation

Students should cross in front of the bus, far enough ahead to be seen by the driver, and only after the driver signals that it is safe. Crossing behind the bus puts students in the driver's blind spot.

Question 44Transporting Passengers Safely

The danger zone around a school bus extends approximately how far from the bus?

  1. 50 feet
  2. 3 feet
  3. 25 feet
  4. 10 feet Correct answer.

Explanation

The danger zone is the area immediately surrounding the bus, roughly 10 feet in all directions, where students are hardest for the driver to see. Drivers must account for this zone when loading and unloading.

Question 45Transporting Passengers Safely

Which of the following is an acceptable reason to leave a school bus unattended with students aboard?

  1. To use a restroom at a terminal
  2. To check the mailbox at a stop
  3. To pick up a schedule at the office
  4. Never; students should not be left unattended on the bus Correct answer.

Explanation

Students must never be left alone on a school bus; the driver remains responsible for their safety at all times. If the driver must leave the bus, students must be supervised or removed first.

Question 46Transporting Passengers Safely

A student is standing in the aisle while the bus is moving. The driver should:

  1. Ask another student to handle the situation
  2. Slow down and allow the student to remain standing
  3. Continue driving and address it at the next stop
  4. Direct the student to sit down immediately before proceeding Correct answer.

Explanation

Students must be seated and secure whenever the bus is in motion. The driver should stop or hold the bus until the student is seated, because standing passengers can be thrown and injured.

Question 47Transporting Passengers Safely

When a school bus is stopped at a railroad crossing, the driver should:

  1. Open the door and listen before crossing Correct answer.
  2. Cross quickly to avoid delaying traffic
  3. Rely on the crossing gate to signal safety
  4. Sound the horn and proceed without stopping

Explanation

At a railroad crossing the driver should stop, open the door or window to listen, and look both ways before proceeding. School buses are required to stop at crossings regardless of signals.

Question 48Transporting Passengers Safely

Which of the following is the correct way to assist a student using a wheelchair onto a school bus?

  1. Ask other students to carry the wheelchair aboard
  2. Use the wheelchair lift and secure the chair with tiedowns Correct answer.
  3. Lift the wheelchair up the steps without using the lift
  4. Have the student walk up the steps and carry the chair separately

Explanation

Wheelchair passengers should be boarded using the lift and then secured with tiedowns and a lap/shoulder belt as designed. Manually lifting a loaded wheelchair is unsafe for both the student and the driver.

Question 49Transporting Passengers Safely

A school bus driver who is being tailgated closely should:

  1. Speed up to create distance
  2. Wave the driver around immediately
  3. Brake sharply to warn the following driver
  4. Increase following distance ahead and avoid sudden stops Correct answer.

Explanation

When tailgated, the driver should leave more room ahead so any stop can be gradual, reducing the chance the following vehicle rear-ends the bus. Sudden braking or speeding up increases risk.

Question 50Transporting Passengers Safely

When driving a school bus in fog, the driver should:

  1. Follow the vehicle ahead closely to use its taillights
  2. Use high-beam headlights for maximum visibility
  3. Turn on hazard lights and maintain the speed limit
  4. Reduce speed and use low-beam headlights Correct answer.

Explanation

In fog, low beams reduce glare and improve visibility better than high beams, and reducing speed gives more time to react. Following closely or maintaining full speed in poor visibility is dangerous.