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Zorluk: Çok zorSpace Ahead and Following Distance

A transportation logistics analyst is evaluating the safety parameters of two different commercial vehicles operating on dry, level pavement.

- Vehicle X is a 6060-foot tractor-trailer traveling at a steady 30 mph30\text{ mph} (equivalent to 44 feet per second44\text{ feet per second}).
- Vehicle Y is a 9090-foot long-combination vehicle (LCV) cruising at 60 mph60\text{ mph} (equivalent to 88 feet per second88\text{ feet per second}).

Based strictly on the standard CDL space ahead formulas, what is the absolute difference, in feet, between the minimum required following distance of Vehicle Y and the minimum required following distance of Vehicle X?

Cevap: 616 feet

Cevap

616
Vehicle X requires 6 seconds of following distance (60 ft / 10), which equates to 264 feet at 44 ft/s. Vehicle Y requires 10 seconds of following distance (90 ft / 10, plus 1 second for exceeding 40 mph), which equates to 880 feet at 88 ft/s. The absolute difference between 880 feet and 264 feet is exactly 616 feet.

Adım Adım Çözüm

1
Determine the required time gap for Vehicle X.
6 seconds
The rule is 1 second per 10 feet of vehicle length. 60 feet / 10 = 6 seconds. Because the speed (30 mph) is under 40 mph, no additional time is added.
2
Convert Vehicle X's time gap into a physical distance.
264 feet
Multiply the time gap by the vehicle's speed in feet per second: 6 seconds * 44 ft/s = 264 feet.
3
Determine the required time gap for Vehicle Y.
10 seconds
The base rule is 1 second per 10 feet of length (90 feet / 10 = 9 seconds). Because the speed (60 mph) is 40 mph or greater, 1 additional second must be added (9 + 1 = 10 seconds).
4
Convert Vehicle Y's time gap into a physical distance.
880 feet
Multiply the time gap by the vehicle's speed in feet per second: 10 seconds * 88 ft/s = 880 feet.
5
Calculate the absolute difference between the two distances.
616 feet
Subtract Vehicle X's distance from Vehicle Y's distance: 880 feet - 264 feet = 616 feet.

Anahtar Kavram

Calculating Following Distance using Speed Thresholds and Distance Conversions
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Konular

Space Ahead and Following Distance

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