A commercial motor carrier is operating a two-axle straight truck coupled to a two-axle eq… — Commercial Driver's License (CDL) General Knowledge Exam

A commercial motor carrier is operating a two-axle straight truck coupled to a two-axle equipment trailer on an interstate route. The vehicle specifications and manufacturer ratings are as follows:

Vehicle Unit	Unladen Curb Weight	Manufacturer GVWR	Manufacturer GCWR
Straight Truck	$12{}200\text{ lbs}$	$26{}000\text{ lbs}$	$38{}000\text{ lbs}$
Equipment Trailer	$4{}500\text{ lbs}$	$15{}000\text{ lbs}$	Not Applicable

If the straight truck is loaded to its maximum Gross Vehicle Weight Rating (GVWR) of $26{}000\text{ lbs}$ , what is the maximum payload weight that can be placed on the equipment trailer without exceeding any manufacturer rating or combination limit?

A
$10{}500\text{ lbs}$
$7{}500\text{ lbs}$ Answer
C
$12{}000\text{ lbs}$
D
$15{}000\text{ lbs}$

Answer

The maximum payload that can be loaded onto the trailer is

7{}500\text{ lbs}

Gross Combination Weight Rating (GCWR) sets the maximum safe operating weight for the entire combination (truck, trailer, and total cargo). Because the straight truck is loaded to its maximum GVWR of

26{}000\text{ lbs}

, the trailer's total gross weight cannot exceed

12{}000\text{ lbs}

(

38{}000\text{ lbs} - 26{}000\text{ lbs}

). Subtracting the trailer's empty curb weight of

4{}500\text{ lbs}

leaves a maximum allowable cargo payload of

7{}500\text{ lbs}

Step-by-Step Solution

Determine the maximum allowable Gross Combination Weight (GCW) for the vehicle configuration.

The towing vehicle's manufacturer GCWR is

38{}000\text{ lbs}

Gross Combination Weight Rating (GCWR) is the maximum allowable total weight of the powered unit, trailer, and all cargo combined.

Calculate the remaining gross weight available for the towed unit when the truck is loaded to its GVWR.

38{}000\text{ lbs} - 26{}000\text{ lbs} = 12{}000\text{ lbs}

The power unit operates at its maximum GVWR of

26{}000\text{ lbs}

, leaving

12{}000\text{ lbs}

of total combination capacity.

Compare the available combination capacity against the trailer's individual GVWR to identify the binding limit.

The GCWR allowance (

12{}000\text{ lbs}

) is lower than the trailer's GVWR (

15{}000\text{ lbs}

), making GCWR the controlling limit.

A combination vehicle must satisfy both individual unit GVWRs and overall GCWR simultaneously; the more restrictive limit governs.

Subtract the trailer's unladen curb weight from the maximum allowable gross trailer weight to find net allowable payload.

12{}000\text{ lbs} - 4{}500\text{ lbs} = 7{}500\text{ lbs}

Payload represents net cargo capacity after accounting for the tare/curb weight of the trailer.

Key Concept

Interaction between Gross Vehicle Weight Rating (GVWR), Gross Combination Weight Rating (GCWR), and net payload calculation

Alternative Method

Calculate the total unladen combination weight first (

12{}200\text{ lbs} + 4{}500\text{ lbs} = 16{}700\text{ lbs}

). The total combination payload capacity is GCWR minus total curb weight (

38{}000\text{ lbs} - 16{}700\text{ lbs} = 21{}300\text{ lbs}

). The truck is carrying

26{}000\text{ lbs} - 12{}200\text{ lbs} = 13{}800\text{ lbs}

of cargo. Subtracting the truck cargo from the combination cargo capacity yields the remaining trailer payload:

21{}300\text{ lbs} - 13{}800\text{ lbs} = 7{}500\text{ lbs}

Estimated Time:2m 0s

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Answer

Step-by-Step Solution

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