A three-axle straight dump truck is scaled prior to traveling on an Interstate highway. Th… — Commercial Driver's License (CDL) General Knowledge Exam

A three-axle straight dump truck is scaled prior to traveling on an Interstate highway. The vehicle identification plate specifies a Gross Vehicle Weight Rating (GVWR) of $58{}000\text{ lbs}$ , a front steer Gross Axle Weight Rating (GAWR) of $18{}000\text{ lbs}$ , and a rear tandem drive GAWR of $40{}000\text{ lbs}$ . Certified scale weights show an actual front steer axle load of $14{}500\text{ lbs}$ and an actual rear tandem axle load of $36{}200\text{ lbs}$ , yielding a total Gross Vehicle Weight (GVW) of $50{}700\text{ lbs}$ . Which of the following statements correctly evaluates the vehicle's compliance with federal weight regulations and manufacturer limits?

A
The vehicle is operating legally because each axle group remains below its manufacturer Gross Axle Weight Rating (GAWR) and the total weight does not exceed the vehicle GVWR.
B
The vehicle is in violation because the front steer axle exceeds the maximum statutory single-axle limit of $12{}000\text{ lbs}$ established under federal highway regulations.
The vehicle is in violation because the rear tandem axle exceeds the federal statutory limit of $34{}000\text{ lbs}$ , despite remaining below the manufacturer GAWR and total GVWR.Answer
D
The vehicle is operating legally on Interstate highways because federal weight enforcement applies solely to the maximum statutory gross limit of $80{}000\text{ lbs}$ .

Answer

The vehicle is in violation because the rear tandem axle exceeds the federal statutory limit of

34{}000\text{ lbs}

, despite remaining below the manufacturer GAWR and total GVWR.

Federal regulations governing the National Network and Interstate highways impose a strict maximum limit of

34{}000\text{ lbs}

on tandem axles and

20{}000\text{ lbs}

on single axles. While the truck's components are engineered to withstand a

40{}000\text{ lbs}

tandem load mechanically (GAWR), the actual load of

36{}200\text{ lbs}

exceeds the statutory legal ceiling by

2{}200\text{ lbs}

, making the operation illegal without an oversize/overweight permit.

Step-by-Step Solution

Evaluate steer axle compliance against manufacturer ratings and federal statutory single-axle limits.

Actual steer load =

14{}500\text{ lbs} \leq 18{}000\text{ lbs}

(GAWR) and

\leq 20{}000\text{ lbs}

(Federal single-axle limit). Status: Compliant.

Federal law allows up to

20{}000\text{ lbs}

on a single axle, constrained by the lower manufacturer GAWR.

Evaluate rear tandem drive axle compliance against manufacturer GAWR and federal statutory tandem limits.

Actual tandem load =

36{}200\text{ lbs} \leq 40{}000\text{ lbs}

(GAWR), but

36{}200\text{ lbs} > 34{}000\text{ lbs}

(Federal statutory tandem limit). Overload =

+2{}200\text{ lbs}

. Status: Non-compliant.

Federal Interstate regulations strictly cap tandem axle weights at

34{}000\text{ lbs}

regardless of higher manufacturer structural ratings.

Evaluate total Gross Vehicle Weight (GVW) against GVWR and federal gross limits.

Actual GVW =

50{}700\text{ lbs} \leq 58{}000\text{ lbs}

(GVWR) and

\leq 80{}000\text{ lbs}

(Federal gross cap). Status: Compliant on gross weight, but overall vehicle is illegal due to axle overload.

A vehicle must satisfy all individual axle limits, bridge formula limits, and total gross caps simultaneously to be legally compliant.

Key Concept

Hierarchy of Weight Limits: Statutory Legal Limits vs. Manufacturer Ratings (GAWR/GVWR)

Estimated Time:1m 30s

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