While transporting cargo in a 60\text{-foot} articulated truck along a dry highway at a cr… — Commercial Driver's License (CDL) General Knowledge Exam

While transporting cargo in a $60\text{-foot}$ articulated truck along a dry highway at a cruising speed of $48\text{ mph}$ , how much total following distance should you maintain behind the vehicle ahead under standard CDL space management guidelines?

A
$3\text{ seconds}$
$7\text{ seconds}$ Answer
C
$8\text{ seconds}$
D
$10\text{ seconds}$

Answer

7\text{ seconds}

of following distance

According to the CDL manual, a driver must maintain at least

1\text{ second}

of following distance for every

10\text{ feet}

of vehicle length at speeds under

40\text{ mph}

. For a

60\text{-foot}

vehicle, the base requirement is

6\text{ seconds}

. Because the vehicle is traveling at

48\text{ mph}

(which is at or above

40\text{ mph}

), an additional

1\text{ second}

must be added, resulting in a total required following distance of

7\text{ seconds}

Step-by-Step Solution

Calculate the base following distance based on vehicle length

\frac{60\text{ ft}}{10\text{ ft/sec}} = 6\text{ seconds}

The standard formula requires

1\text{ second}

of following distance for every

10\text{ feet}

of vehicle length.

Evaluate the vehicle speed and apply speed-related adjustments

Speed is

48\text{ mph}

, which is

\ge 40\text{ mph}

, so add

1\text{ second}

When operating at speeds at or above

40\text{ mph}

, drivers must add

1\text{ additional second}

to account for increased braking distance and reaction time.

Sum the base following distance and the speed adjustment

6\text{ seconds} + 1\text{ second} = 7\text{ seconds}

Total minimum safe following distance is the sum of the vehicle length allowance and the highway speed adjustment.

Key Concept

Calculating minimum safe following distance for commercial motor vehicles using the length and speed formula

Estimated Time:1m 0s

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic