A driver is operating a 55-foot commercial flatbed truck at a steady speed of 45\text{ mph… — Commercial Driver's License (CDL) General Knowledge Exam

A driver is operating a $55$ -foot commercial flatbed truck at a steady speed of $45\text{ mph}$ along a dry, two-lane highway under clear daylight conditions. According to standard commercial vehicle safety formulas, what is the minimum following distance the driver must maintain behind the preceding vehicle?

A
$3.0\text{ seconds}$
B
$5.5\text{ seconds}$
$6.5\text{ seconds}$ Cevap
D
$7.5\text{ seconds}$

Cevap

The minimum safe following distance is

6.5\text{ seconds}

The correct following distance for a

55

-foot commercial vehicle traveling at

45\text{ mph}

6.5\text{ seconds}

. The base requirement is

1\text{ second}

per

10\text{ feet}

of vehicle length (

5.5\text{ seconds}

). Because the vehicle is operating above

40\text{ mph}

, an additional

1\text{ second}

must be added (

5.5 + 1.0 = 6.5\text{ seconds}

Adım Adım Çözüm

Calculate base following distance from vehicle length

5.5\text{ seconds}

The standard commercial driving rule requires

1\text{ second}

of following distance for every

10\text{ feet}

of vehicle length:

\frac{55\text{ ft}}{10\text{ ft/sec}} = 5.5\text{ seconds}

Apply speed modifier for travel at or above

40\text{ mph}

+1.0\text{ second}

At speeds of

40\text{ mph}

and higher, drivers must add

1\text{ additional second}

for safety due to increased total stopping distance.

Combine base time and speed modifier

5.5\text{ s} + 1.0\text{ s} = 6.5\text{ seconds}

Summing the vehicle length component and the higher-speed buffer gives the total minimum required time cushion.

Anahtar Kavram

CDL Standard Following Distance Formula: 1 second per 10 feet of vehicle length under 40 mph, plus 1 additional second for speeds at or above 40 mph.

Tahmini Süre:1m 0s

Soru

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