Speed & Space Management

Study questions with answers

12 sample Speed & Space Management questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.

1. 1. How far ahead do good drivers generally look while driving?

   Correct answer: About 12 to 15 seconds ahead

   Good drivers look ahead about 12 to 15 seconds, which is roughly one block at city speeds and about a quarter mile at highway speeds.

   Source: Ohio CDL Driver Manual, Section 2 (Seeing Ahead)

2. 2. If your vehicle begins to hydroplane, what is the correct response?

   Correct answer: Release the accelerator and push in the clutch

   Do not brake when hydroplaning. Instead, ease off the accelerator and push in the clutch so the wheels can slow and turn freely to regain traction.

   Source: Ohio CDL Driver Manual, Section 2 (Hydroplaning)

3. 3. In many states, how much lower can the speed limit for trucks and buses be compared with cars?

   Correct answer: As much as 15 mph

   Truck and bus speed limits can be as much as 15 mph lower than the limits for cars, so use extra caution when changing lanes or passing on such roads.

   Source: Ohio CDL Driver Manual, Section 2 (Speed and Traffic Flow)

4. 4. At speeds under 40 mph, how much following distance does the manual suggest for vehicle length?

   Correct answer: One second for every 10 feet of vehicle length

   Below 40 mph, allow about one second of following distance for each 10 feet of your vehicle's length. Above 40 mph you add one more second.

   Source: Ohio CDL Driver Manual, Section 2 (Space Ahead)

5. 5. How should you handle your speed and gear before entering a curve on the road test?

   Correct answer: Slow before the curve so no braking or shifting is needed in it

   Reduce your speed before entering the curve so that no further braking or shifting is needed within it, and keep the vehicle in its lane throughout.

   Source: Ohio CDL Driver Manual, Section 13 (Curve)

6. 6. Before starting down a long, steep grade, what should you do with your transmission?

   Correct answer: Shift into a low gear before the descent

   Shift into a low gear before you start down the grade. Do not wait, because once your speed builds up you may not be able to downshift and could lose all engine braking.

   Source: Ohio CDL Driver Manual, Section 2 (Select the Right Gear)

7. 7. According to the manual, what is the total stopping distance for a vehicle at 55 mph under ideal conditions?

   Correct answer: About 419 feet

   At 55 mph, adding perception, reaction, and braking distances gives a minimum total of about 419 feet before the vehicle can come to a complete stop.

   Source: Ohio CDL Driver Manual, Section 2 (Total Stopping Distance)

8. 8. Total stopping distance is made up of which three parts added together?

   Correct answer: Perception distance, reaction distance, and braking distance

   Total stopping distance combines perception distance, reaction distance, and braking distance. Understanding each helps explain why big vehicles need so much room to stop.

   Source: Ohio CDL Driver Manual, Section 2 (Stopping Distance)

9. 9. Why is an empty cargo van taller than the same van fully loaded?

   Correct answer: The load compresses the suspension and lowers the loaded van

   Cargo weight compresses the suspension, so a loaded van sits lower. An empty one rides higher, meaning clearing a bridge loaded does not guarantee you will clear it empty.

   Source: Ohio CDL Driver Manual, Section 2 (Space Overhead)

10. 10. On a wet road, about how much should you cut your speed?

    Correct answer: By about one-third

    On wet pavement, reduce your speed by roughly one-third; for example, dropping from 55 mph to around 35 mph. On packed snow you cut speed by half or more.

    Source: Ohio CDL Driver Manual, Section 2 (Slippery Surfaces)

11. 11. By roughly how much can a wet road increase your stopping distance compared with dry pavement?

    Correct answer: It can double the distance

    A wet road can double the distance needed to stop, so you should slow down to keep your true stopping distance within a safe range.

    Source: Ohio CDL Driver Manual, Section 2 (Matching Speed to the Road)

12. 12. How does the following-distance rule change once you are traveling faster than 40 mph?

    Correct answer: You add one second

    At speeds over 40 mph you add one extra second to the length-based count. A 40-foot vehicle needing 4 seconds below 40 mph needs 5 seconds above it.

    Source: Ohio CDL Driver Manual, Section 2 (Space Ahead)