South Dakota: Speed and following distance
Looking ahead, adjusting speed to the road and weather, stopping distance, the four-second following distance and space around your vehicle. Split into 3 shorter tests so you're not stuck in one long quiz.
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Speed and following distance — Part 1
Questions in this part include: “What does stopping suddenly usually point to?”
StartSpeed and following distance — Part 2
Questions in this part include: “What is total stopping distance?”
StartSpeed and following distance — Part 3
Looking ahead, adjusting speed to the road and weather, stopping distance, the four-second following distance and space around your vehicle. — Part 3
StartAll 52 Speed and following distance questions with answers
Choose a part above to take a practice test, or study every question and answer here.
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What does stopping suddenly usually point to?
- A driver with a worn clutch
- A driver who is too far from the curb
- A driver in a good vehicle
- A driver who was not paying attention
Show answer
Correct answer: A driver who was not paying attention
The manual says stopping suddenly is dangerous and usually points to a driver who was not paying attention.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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What can happen when you brake quickly?
- You will always stop in a much shorter distance than usual
- You could skid, and drivers behind may not be able to stop in time
- Your tires will grip the road better on a slippery surface
- Drivers behind will have more room
Show answer
Correct answer: You could skid, and drivers behind may not be able to stop in time
Quick braking can make you skid and lose control, and it makes it harder for drivers behind you to stop.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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How can you avoid panic stops?
- By braking only at the last moment
- By following other vehicles closely so you can brake together
- By seeing events well in advance and slowing down or changing lanes
- By driving in the left lane at all times
Show answer
Correct answer: By seeing events well in advance and slowing down or changing lanes
Seeing events well in advance lets you slow down or change lanes and make a more gradual, safer stop.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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According to the manual, what is the best way not to speed?
- Follow the speed of the vehicle ahead of you closely
- Judge your speed by the sound of the engine and tires
- Drive with the flow of traffic
- Know how fast you are going by checking the speedometer often
Show answer
Correct answer: Know how fast you are going by checking the speedometer often
The manual says the best way not to speed is to know how fast you are going and to check the speedometer often.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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What does the manual say about how well people judge their own speed?
- People judge their speed accurately
- Only new drivers misjudge their speed
- People judge slow speeds poorly but fast speeds well
- People are not very good at judging how fast they are going
Show answer
Correct answer: People are not very good at judging how fast they are going
The manual notes that people are not very good at judging their speed, so the speedometer should be checked.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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When is it especially easy to be traveling much faster than you think?
- When you leave slow local roads and enter high speed roads
- When you leave high speed roads for much slower local roads
- When you drive at night
- When you drive in the rain
Show answer
Correct answer: When you leave high speed roads for much slower local roads
It is especially easy to drive faster than you think when you leave high speed roads for slower local roads.
Source: South Dakota Driver License Manual (Revised 11/2024), page 29
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The maximum speed limit should be driven only in what conditions?
- Daylight hours only
- Ideal driving conditions
- Rural areas only
- Any conditions, because it is the legal limit
Show answer
Correct answer: Ideal driving conditions
The posted maximum is for ideal conditions, and you must slow down when conditions require it.
Source: South Dakota Driver License Manual (Revised 11/2024), page 35
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Why are minimum speed limits posted on some high-speed roads?
- So slow drivers are not a hazard to others
- So drivers save fuel on long trips
- So drivers have time to read road signs
- So traffic noise is kept low near towns
Show answer
Correct answer: So slow drivers are not a hazard to others
Drivers must travel at least the minimum speed so they do not become a hazard to other drivers.
Source: South Dakota Driver License Manual (Revised 11/2024), page 35
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The minimum posted speed on a road is too fast for you. What should you do?
- Drive in the right lane at a slower speed
- Turn on your hazard lights and drive slower
- Use another road
- Drive at the maximum limit instead
Show answer
Correct answer: Use another road
If you cannot drive at the minimum speed, the manual says to use another road.
Source: South Dakota Driver License Manual (Revised 11/2024), page 35
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According to the manual, how much time does speeding save?
- Only a few minutes for each hour of driving
- About half an hour for each hour of driving
- A large amount of time on every long trip
- About ten minutes for each mile driven
Show answer
Correct answer: Only a few minutes for each hour of driving
Speeding does not save more than a few minutes for each hour of driving.
Source: South Dakota Driver License Manual (Revised 11/2024), page 45
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What can happen if you drive much slower than other vehicles?
- You can be ticketed for impeding traffic
- Nothing, because slow driving is always safe
- Your license will be suspended automatically
- Your vehicle will be impounded
Show answer
Correct answer: You can be ticketed for impeding traffic
Driving much slower than other traffic is dangerous and you can be ticketed for impeding traffic.
Source: South Dakota Driver License Manual (Revised 11/2024), page 45
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If vehicles are lined up behind you, what should you do?
- Slow down further to discourage passing
- Speed up above the posted limit
- Pull over when safe and let them pass
- Stop in your lane and wave them past
Show answer
Correct answer: Pull over when safe and let them pass
You should pull over when it is safe to do so and let the vehicles pass.
Source: South Dakota Driver License Manual (Revised 11/2024), page 45
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When you turn from a high-speed, two-lane roadway with traffic following you, what should you try not to do?
- Signal your turn
- Slow down too early
- Tap the brakes
- Reduce your speed
Show answer
Correct answer: Slow down too early
The manual says to try not to slow down too early, tapping the brakes quickly but safely to reduce speed.
Source: South Dakota Driver License Manual (Revised 11/2024), page 45
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Which vehicles can lose speed on long or steep uphill climbs?
- Only large trucks and buses
- Only small cars and motorcycles
- Only farm tractors and wagons
- Large trucks and small cars
Show answer
Correct answer: Large trucks and small cars
Large trucks and small cars can lose speed on long or steep climbs and take longer to get up to speed when entering traffic.
Source: South Dakota Driver License Manual (Revised 11/2024), page 45
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Why should you slow down at narrow bridges and tunnels?
- The pavement is usually rougher than on open roads
- Vehicles from opposite sides pass closer together
- Traffic signals on them change more quickly
- Passing is required on them
Show answer
Correct answer: Vehicles from opposite sides pass closer together
Narrow bridges and tunnels force vehicles approaching from opposite sides closer together.
Source: South Dakota Driver License Manual (Revised 11/2024), page 46
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How far ahead should you ideally try to look at what is occurring?
- 20 to 30 seconds in front of the car
- 5 to 10 seconds in front of the car
- 10 to 15 seconds in front of the car
- 40 to 50 seconds in front of the car
Show answer
Correct answer: 20 to 30 seconds in front of the car
Looking well down your planned path gives you time to adjust and avoid emergency braking. The manual says to look about 20 to 30 seconds ahead.
Source: South Dakota Driver License Manual (Revised 11/2024), page 48
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Which situation can limit how far you are able to see ahead?
- Driving on a highway in daylight
- Keeping a large space cushion ahead
- Following too close to a larger vehicle
- Looking well down the planned path
Show answer
Correct answer: Following too close to a larger vehicle
A large vehicle in front blocks your view of the road. The manual says to avoid following too close to one and to adjust your speed and position so you can see.
Source: South Dakota Driver License Manual (Revised 11/2024), page 48
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How does looking well ahead help you save fuel?
- You can drive with the engine off on hills
- You avoid unnecessary quick stops that lower miles per gallon
- You can follow closer to the vehicle ahead and brake less
- You can use the high beams more often
Show answer
Correct answer: You avoid unnecessary quick stops that lower miles per gallon
Quick stops cost time and fuel to get back up to speed. Drivers who look ahead can slow gradually or change lanes instead.
Source: South Dakota Driver License Manual (Revised 11/2024), page 48
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What could happen if you brake hard after entering a curve?
- The brakes would grip better
- The tires could lose traction
- The vehicle would stop in a straighter line
- The steering would become lighter
Show answer
Correct answer: The tires could lose traction
Hard braking in a curve can cause the tires to lose traction, so reduce speed before entering.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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When should you reduce your speed for a curve?
- Halfway through the curve
- Only after you see the end of the curve
- After the curve begins to tighten
- Before entering the curve
Show answer
Correct answer: Before entering the curve
The manual says to always reduce speed before entering a curve to a safe speed.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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Which situation calls for reducing speed even more in a curve?
- When traction is good
- When there are no vehicles in front of you
- When you cannot see the end of the curve
- When it is daylight
Show answer
Correct answer: When you cannot see the end of the curve
Reduce speed more when traction is poor, when following other vehicles and when you cannot see the end of the curve.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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When should you reduce your speed on a slippery road?
- At the first sign of rain, snow, sleet, or ice
- Only after the vehicle starts to skid
- Only when the road is fully covered in ice
- Only if other drivers have slowed down
Show answer
Correct answer: At the first sign of rain, snow, sleet, or ice
Wet or icy surfaces reduce grip, so it takes longer to stop and harder to turn without skidding.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What is hydroplaning?
- The brakes overheat after long use on a long downhill
- The tires lose air pressure on wet pavement
- The engine stalls when it gets wet
- The steering tires ride up on pooled water, like water skis
Show answer
Correct answer: The steering tires ride up on pooled water, like water skis
Hydroplaning is when the steering tires start to ride up on pooled water.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What is the best way to avoid traction loss from hydroplaning?
- Brake hard when you feel the tires slide
- Slow down in the rain or when the road has pooled water
- Speed up so the tires push through the water
- Turn the steering wheel sharply left and right
Show answer
Correct answer: Slow down in the rain or when the road has pooled water
Slowing down in the rain or on roads with puddles is the manual’s best way to avoid hydroplaning.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What is total stopping distance?
- The distance the vehicle travels from the moment the brakes are first pressed until it stops
- The distance you can see ahead on a clear day in good light
- The distance between your vehicle and the one in front of you
- The distance the vehicle travels, in ideal conditions, from the time you realize you must stop until it stops
Show answer
Correct answer: The distance the vehicle travels, in ideal conditions, from the time you realize you must stop until it stops
It counts the distance from the moment you realize you must stop until the vehicle has stopped.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What is the average perception time for an alert driver?
- ¾ second to 1 second
- 2 to 3 seconds
- 1½ to 2 seconds
- ¼ second to ½ second
Show answer
Correct answer: ¾ second to 1 second
Perception time is the time and distance it takes to recognize that you must stop.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What does your reaction time include?
- Recognizing that you must stop and what to do next
- The time the brakes take to stop the vehicle
- Moving your foot from the gas pedal and starting to brake
- The time you spend looking in the mirrors
Show answer
Correct answer: Moving your foot from the gas pedal and starting to brake
Reaction time is the time and distance it takes to move your foot from the gas pedal and begin braking.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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At 50 mph on dry pavement with good brakes, how far can braking distance be?
- About 50 feet
- About 100 feet
- About 250 feet
- About 158 feet
Show answer
Correct answer: About 158 feet
The manual gives about 158 feet of braking distance at 50 mph on dry pavement with good brakes.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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How does speed affect stopping distance?
- Speed has no effect on how far the vehicle needs to stop
- The faster you travel, the more time and distance you need to stop
- Only braking distance changes with speed
- Only reaction time changes with speed
Show answer
Correct answer: The faster you travel, the more time and distance you need to stop
Speed is one of the factors that affects stopping distance: more speed means more distance.
Source: South Dakota Driver License Manual (Revised 11/2024), page 50
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What minimum following distance should you always try to keep behind the vehicle in front?
- 1 second
- 2 seconds
- 4 seconds
- 3 seconds
Show answer
Correct answer: 4 seconds
Following closely limits your view and your time to react, so keep at least 4 seconds between your car and the vehicle ahead.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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How do you determine your following distance?
- Count the seconds until you reach the point the car ahead passed
- Count the car lengths between you and the vehicle ahead
- Compare your speed to the posted limit
- Count the lane lines between the two vehicles
Show answer
Correct answer: Count the seconds until you reach the point the car ahead passed
You pick a stationary point such as a sign or pole, watch the vehicle ahead pass it, and count the seconds until you reach it.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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You reach a stationary point before counting “one thousand four” after the vehicle ahead passed it. What does that mean?
- You are following too closely
- You are following at a safe distance
- You are driving above the speed limit
- You need to speed up to keep pace
Show answer
Correct answer: You are following too closely
Passing the point before counting to one thousand four means you are following too closely, so reduce speed and count again.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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On slippery roads, why must you leave more space in front of you?
- Tires wear faster on wet pavement
- Other drivers will pass you more often
- You need more distance to stop the vehicle
- Your headlights shine less far ahead
Show answer
Correct answer: You need more distance to stop the vehicle
If the vehicle ahead suddenly stops on a slippery road, you will need the extra distance to stop safely.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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When the driver behind you wants to pass, what should you do?
- Speed up to stay ahead of the pass
- Slow down to allow room in front of you
- Move onto the shoulder and stop
- Keep your speed and hold your lane
Show answer
Correct answer: Slow down to allow room in front of you
Slowing gives room in front of your vehicle and lets the pass be completed sooner.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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Why should you increase your following distance when hauling a heavy load or pulling a trailer?
- The trailer reduces your top speed on the highway
- The trailer makes the turn signals harder to see
- The tires wear faster with extra weight
- The extra weight increases the stopping distance
Show answer
Correct answer: The extra weight increases the stopping distance
More weight means a longer distance is needed to stop.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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When it is hard to see because of darkness or bad weather, what should you do?
- Follow the vehicle ahead more closely
- Increase your following distance
- Keep the same following distance
- Tap the horn as you follow
Show answer
Correct answer: Increase your following distance
A bigger following distance lets you see ahead or have time to stop if necessary.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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If someone is following you closely, what should you do about the space in front of you?
- Keep a short gap so the driver behind stays well back
- Allow extra room so you can stop without being hit from behind
- Brake hard to warn the driver behind
- Move closer to the vehicle ahead
Show answer
Correct answer: Allow extra room so you can stop without being hit from behind
Extra room in front lets you stop gradually without being hit from behind.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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Why should you leave extra room when stopped on a hill or incline?
- The brakes work less well when you are on a hill
- The vehicle ahead may run out of fuel
- Drivers behind you will want to pass
- The vehicle ahead may roll back when it starts moving
Show answer
Correct answer: The vehicle ahead may roll back when it starts moving
A vehicle starting uphill can roll back, so extra space protects you.
Source: South Dakota Driver License Manual (Revised 11/2024), page 51
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Why should you avoid driving next to other vehicles for long periods of time?
- It uses more fuel than driving behind them in the same lane
- It makes the other driver speed up
- You may be in their blind spot, and have less room to avoid a crash
- It is against the law in every lane
Show answer
Correct answer: You may be in their blind spot, and have less room to avoid a crash
Driving alongside puts you where the other driver may not see you and leaves less room to react.
Source: South Dakota Driver License Manual (Revised 11/2024), page 52
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What should you avoid doing in relation to the center line marking?
- Looking at it
- Driving on the right side of it
- Slowing near it
- Crowding it
Show answer
Correct answer: Crowding it
Keep as much space as possible between you and oncoming traffic.
Source: South Dakota Driver License Manual (Revised 11/2024), page 52
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How can you help a driver behind you keep a safe distance?
- Drive slightly faster than the posted limit at all times
- Tap the brakes often to warn the driver
- Stay close to the center line
- Keep a steady speed and signal early before you slow or turn
Show answer
Correct answer: Keep a steady speed and signal early before you slow or turn
A steady speed and early signals give the driver behind you time to react.
Source: South Dakota Driver License Manual (Revised 11/2024), page 52
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How much should you add to your following distance for night driving conditions?
- At least half a second
- At least one additional second
- At least three additional seconds
- At least five additional seconds
Show answer
Correct answer: At least one additional second
The manual says to add at least one extra second of following distance for night conditions.
Source: South Dakota Driver License Manual (Revised 11/2024), page 66
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How much should you add to your following distance when driving on an unfamiliar roadway at night?
- At least two additional seconds
- At least one additional second
- At least four additional seconds
- No extra time if you use high beams
Show answer
Correct answer: At least two additional seconds
For unfamiliar roads at night, add at least two extra seconds of following distance.
Source: South Dakota Driver License Manual (Revised 11/2024), page 66
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What is the "first is worst" warning about winter driving?
- The first car on a road clears the snow for everyone behind it, so follow closely
- The first snowfall of the year is always the heaviest one, so avoid driving
- In the first storm of the season, most drivers have forgotten their safe winter driving skills
- The first driver at a snowy intersection always has the right-of-way over others
Show answer
Correct answer: In the first storm of the season, most drivers have forgotten their safe winter driving skills
In the first storm of the season, drivers tend to drive too fast and stop too quickly, so you should go slowly and relearn your skills.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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What mistakes do most drivers make in the first storm of the season?
- They drive too slowly and stop too late
- They drive too fast and try to stop too quickly
- They follow too far behind and brake too gently
- They use high beams and turn too sharply
Show answer
Correct answer: They drive too fast and try to stop too quickly
Drivers who have forgotten their winter skills tend to drive too fast and brake too hard.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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How fast should you drive in winter conditions?
- At the posted speed limit
- Slightly above the posted speed limit
- At the speed of the vehicle ahead
- Well below the posted speed limit
Show answer
Correct answer: Well below the posted speed limit
The manual tells you to go slowly and drive well below the posted limit in winter.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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For what conditions are posted speed limits intended, according to the winter driving tips?
- Any season on wet pavement
- Daytime driving in any weather
- Summer months on dry pavement
- Rural roads only
Show answer
Correct answer: Summer months on dry pavement
Posted limits assume summer and dry pavement, so snow and ice call for a lower speed.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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What can happen when you try to stop on a gravel or dirt road?
- The brakes will lock automatically
- You may skid
- The vehicle will stop in a shorter distance
- The tires will grip better than on pavement
Show answer
Correct answer: You may skid
Traction is reduced on gravel or dirt, so you should slow down, follow farther back, and expect to skid when stopping.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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What should you do on a narrow rural road that may have ditches or drop offs instead of shoulders?
- Drive on the right edge of the road to leave more room for others
- Increase your speed to get through the narrow part of the road quickly
- Drive on the left side of the road to see farther ahead of you
- Reduce speed, center the vehicle in the lane, and watch for oncoming traffic
Show answer
Correct answer: Reduce speed, center the vehicle in the lane, and watch for oncoming traffic
Narrow rural roads have little margin, so you slow down, center your vehicle, and watch for oncoming traffic that may come into your lane.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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What should you do when driving over open bridge gratings or steel bridges?
- Speed up to cross quickly and loosen your grip on the steering wheel
- Reduce speed and brake hard once you are on the steel bridge surface
- Keep your speed and follow closer to the vehicle ahead of you
- Reduce speed, increase following distance, and keep a firm grip on the wheel
Show answer
Correct answer: Reduce speed, increase following distance, and keep a firm grip on the wheel
Open gratings and steel bridges reduce traction, so you slow down, leave more space, and hold the wheel firmly.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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Which of these can create blind corners and limit how far you can see on rural roads?
- Paved shoulders
- Crops growing in fields
- Wide lanes
- Painted center lines
Show answer
Correct answer: Crops growing in fields
Wooded areas, crops growing in fields, and steep hills can all limit your view on rural roads.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67
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What should you always do in areas of reduced vision on rural roads?
- Sound your horn and keep your speed
- Move to the shoulder
- Use your high beams during the day
- Reduce speed and be prepared to stop
Show answer
Correct answer: Reduce speed and be prepared to stop
When you cannot see far ahead, slow down and be ready to stop.
Source: South Dakota Driver License Manual (Revised 11/2024), page 67