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Zorluk: OrtaSpace Ahead and Following Distance

While operating a 35-foot35\text{-foot} single-unit commercial motorcoach at a constant speed of 45 mph45\text{ mph} on a clear, dry highway, what is the minimum following distance in seconds that the driver must maintain behind the vehicle ahead?

  1. A
    3.5 seconds3.5\text{ seconds}
  2. B
    2.0 seconds2.0\text{ seconds}
  3. 4.5 seconds4.5\text{ seconds}Cevap
  4. D
    5.5 seconds5.5\text{ seconds}

Cevap

The minimum safe following distance is 4.5 seconds4.5\text{ seconds}.
According to official CDL guidelines, commercial drivers must allow at least 1 second1\text{ second} for every 10 feet10\text{ feet} of vehicle length when traveling under 40 mph40\text{ mph}. For a 35-foot35\text{-foot} vehicle, this yields 3.5 seconds3.5\text{ seconds}. Because the vehicle is traveling at 45 mph45\text{ mph} (which is at or above 40 mph40\text{ mph}), 1 additional second1\text{ additional second} must be added, totaling 4.5 seconds4.5\text{ seconds}.

Adım Adım Çözüm

1
Calculate base following interval based on vehicle length
35 feet10 feet/second=3.5 seconds\frac{35\text{ feet}}{10\text{ feet/second}} = 3.5\text{ seconds}
The standard CDL formula requires 1 second of space ahead for every 10 feet of vehicle length.
2
Determine speed adjustment for operating at or above 40 mph
Add 1.0 second1.0\text{ second} because the operating speed is 45 mph45\text{ mph}
When operating at speeds of 40 mph or greater, drivers must add 1 additional second to account for increased stopping distance.
3
Sum base interval and speed adjustment
3.5 seconds+1.0 second=4.5 seconds3.5\text{ seconds} + 1.0\text{ second} = 4.5\text{ seconds}
Total required following distance under ideal conditions is the sum of the length-based time and the speed modifier.

Anahtar Kavram

CDL Safe Following Distance Rule (1 second per 10 feet of vehicle length, plus 1 second for speeds at or over 40 mph)
Tahmini Süre:1m 0s
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