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. Trucks with a high center of gravity that take a curve too fast may:

   Correct answer: roll over even at the posted speed for the curve

   Tests show high-center-of-gravity trucks can roll over even at the posted speed for the curve, so slow before entering.

   Source: KY CDL Manual, Sec 2.6 Speed and Curves

2. 2. At speeds below 40 mph, the recommended following distance is at least:

   Correct answer: one second for every 10 feet of your rig's length

   Allow at least one second for every 10 feet of your rig's length below 40 mph, and add one more second at higher speeds.

   Source: KY CDL Manual, Sec 2.7 Space Ahead

3. 3. Total stopping distance is made up of perception distance, reaction distance, and:

   Correct answer: braking distance

   Total stopping distance equals perception distance plus reaction distance plus braking distance.

   Source: KY CDL Manual, Sec 2.6 Stopping Distance

4. 4. You should slow to a safe speed for a curve:

   Correct answer: before you enter it, not while turning

   Slow before the curve; braking while turning makes it easier to lock the wheels and skid.

   Source: KY CDL Manual, Sec 2.6 Speed and Curves

5. 5. On packed snow, by about how much should you reduce your speed?

   Correct answer: By about half or more

   On packed snow, reduce your speed by a half; on ice, slow to a crawl and stop as soon as it is safe.

   Source: KY CDL Manual, Sec 2.6 Matching Speed to the Road Surface

6. 6. On a wet road, by about how much should you reduce your speed?

   Correct answer: About one-third

   Wet roads can double stopping distance, so cut your speed by about one-third; on packed snow, reduce it by half.

   Source: KY CDL Manual, Sec 2.6 Matching Speed to the Road Surface

7. 7. Compared with hydraulic brakes, air brakes add an extra delay to stopping known as:

   Correct answer: brake lag

   Air brakes take about a half second or more for air to reach the brakes, called brake lag, adding roughly 32 feet at 55 mph.

   Source: KY CDL Manual, Sec 5.4 Stopping Distance

8. 8. If your vehicle begins to hydroplane, you should:

   Correct answer: release the accelerator and push in the clutch

   Regain control by releasing the accelerator and pushing in the clutch; do not use the brakes while hydroplaning.

   Source: KY CDL Manual, Sec 2.6 Hydroplaning

9. 9. Regarding overhead clearance, an empty cargo van is:

   Correct answer: higher than the same van when loaded

   The weight of a cargo van changes its height; an empty van is higher than a loaded one, so clearing a bridge loaded does not mean you can clear it empty.

   Source: KY CDL Manual, Sec 2.7 Space Overhead

10. 10. In heavy traffic, the safest speed is generally:

    Correct answer: the speed of the other vehicles, without exceeding limits

    Vehicles going the same direction at the same speed are least likely to collide; match the flow without going at an illegal or unsafe speed.

    Source: KY CDL Manual, Sec 2.6 Speed and Traffic Flow

11. 11. Hydroplaning can begin at speeds as low as:

    Correct answer: 30 mph when there is a lot of water

    Hydroplaning can occur at speeds as low as 30 mph when there is a lot of water, especially with worn tread or low tire pressure.

    Source: KY CDL Manual, Sec 2.6 Hydroplaning

12. 12. For a 60-foot rig traveling faster than 40 mph, the recommended following distance is:

    Correct answer: 7 seconds

    A 60-foot rig needs 6 seconds below 40 mph; add one second above 40 mph, for a total of 7 seconds.

    Source: KY CDL Manual, Sec 2.7 Space Ahead