If a North Carolina truck has four axles total but only three of them are touching the road (one lift axle is raised), does it count as a four-axle truck for the higher gross-weight limit, or as a three-axle truck capped at 47,500 pounds?
Plain-English summary
J. G. Wilson, Director of License, Theft and Weight Enforcement at the Division of Motor Vehicles, asked the AG a practical enforcement question. North Carolina law set gross-weight limits that depended on the number of axles. G.S. 20-118(9) capped three-axle trucks at 47,500 pounds. G.S. 20-118(10) raised the cap to 64,000 pounds for trucks with four or more axles. Some trucks were equipped with a fourth axle that could be raised and lowered (the "air bag" axle). When the lift axle was up, only three axles were touching the road and bearing weight. Did such a truck still qualify for the four-axle limit, or was it a three-axle truck for weight-enforcement purposes?
The 1983 AG concluded the four-axle limit applies only when the axles are actually carrying load. A truck with a raised, non-load-bearing axle is treated as a three-axle truck even though the total axle count is four. The legislative purpose behind the axle-based weight schedule is to control the pressure each axle places on the roadway. A raised axle bears no load, places no pressure on the roadway, and therefore should not count toward the threshold that authorizes a higher gross weight.
The opinion's analytic move is one of plain legislative intent. The AG cited Strong's North Carolina Index 3d (Statutes § 5.1) for the proposition that "the intent and spirit of an act are controlling in its construction." The intent of the four-axle limit was to allow heavier loads only where the load was spread over four contact points; raising the fourth axle defeats that distribution and pushes the load onto the remaining three. Reading the statute literally to allow the higher weight despite the raised axle would let operators evade the spirit of the schedule.
The practical consequence: a truck operating with three axles down and exceeding 47,500 pounds gross weight is subject to the penalties for exceeding the three-axle limit, regardless of whether a fourth axle is mechanically present.
Currency note
This opinion was issued in 1983. Subsequent statutory amendments, court decisions, or later AG opinions may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here. North Carolina's truck-weight schedule under Chapter 20 has been revised multiple times to align with federal interstate-highway weight standards and to address bridge-formula calculations, axle-spacing rules, and special permits. The basic principle (lift axles count only when down) has been preserved by enforcement practice and embedded in federal-state harmonized rules, but specific weight limits, axle-grouping definitions, and permit exceptions should be verified against the current statutes and DMV enforcement manuals.
Historical context: what the AG concluded
The 1983 opinion's reasoning is short but useful as a model of purposive statutory construction.
It identified the legislative purpose precisely. Weight schedules tied to axle count exist because per-axle load is what damages road surfaces. The four-axle premium was a reward for spreading the load over an additional contact point. Reading the schedule to allow a four-axle truck to operate at the higher weight with one axle raised would give the operator the premium without delivering the load distribution.
It avoided a textualist reading that would have produced an anomaly. A pure count-the-axles reading would say four mechanical axles means four axles, period. The AG declined that reading because it produced a result inconsistent with the schedule's purpose.
It treated enforcement as a real-world act. The weight-enforcement officer at the scales sees what is touching the road. The lift axle's status is observable. The opinion's rule produces an enforceable standard: count axles that are down at the moment of weighing.
It did not address borderline mechanical questions. The opinion does not analyze what happens if a lift axle is partially deployed, or if the lift axle deploys automatically when load increases, or if the operator can show the axle would deploy on the open road. Those questions were left for case-by-case enforcement and would be developed by subsequent practice and litigation.
Background and statutory framework
G.S. 20-118 sets axle-based gross-weight limits for vehicles operating on North Carolina highways. In 1983, subsection (9) capped the gross weight of a vehicle or combination with three axles at 47,500 pounds. Subsection (10) capped a vehicle or combination with four or more axles at 64,000 pounds. The difference reflects the engineering judgment that more axles distribute weight more broadly and produce less pavement damage per pound carried.
Lift axles (sometimes called "air bag" axles, after the suspension mechanism that raises and lowers them) are mechanical fourth or fifth axles that can be deployed when the truck is heavily loaded and stowed when the truck is lightly loaded. They allow operators to vary the truck's effective axle count to match the load.
The DMV's weight-enforcement program operated through fixed scales and portable units. Officers at the scales would observe the truck's configuration, weigh it, and determine compliance with the applicable limit. The question of how to treat a lifted axle at weighing was a practical enforcement issue that the Division asked the AG to resolve.
Strong's North Carolina Index 3d, Statutes § 5.1, articulates the general rule of purposive construction: "The intent and spirit of an act are controlling in its construction. In ascertaining this intent the courts should consider the language of the statute, the spirit of the Act and what it sought to accomplish."
Common questions
Can a driver lower the lift axle right before the scale?
The 1983 opinion does not address timing. As a practical matter, weight-enforcement scales weigh the truck in its current configuration. A driver who lowers the axle before weighing presents a four-axle truck to the scale; the question of whether the axle was lowered with the intent to evade the limit is a separate evidentiary issue.
What if the lift axle would have deployed automatically once on the highway?
The opinion does not analyze automatic deployment systems. The rule it announces is "if it isn't down, it doesn't count." A truck whose lift axle deploys automatically at speed but is up at the scale is, at the scale moment, a three-axle truck under this rule.
Does this apply to tractor-trailer combinations as well as single trucks?
G.S. 20-118(9) and (10) both refer to "any vehicle or combination of vehicles" with the specified axle count. The same load-bearing principle applies. A tractor-trailer with a lifted trailer axle is counted at the load-bearing axle count.
Are there permits for higher weights with lift axles deployed?
The opinion does not address overweight permits. North Carolina has a permit system for oversize and overweight loads administered by the DMV. The 1983 opinion deals with operation within the standard weight schedule, not with permitted overweight operation.
What penalty applies to a violation?
The opinion does not specify the penalty schedule. G.S. 20-118 carries civil penalties calibrated to the amount of overweight. The DMV's weight-enforcement manual specifies the per-pound or per-bracket fine structure in effect at any given time.
Source
- Landing page: https://ncdoj.gov/opinions/motor-vehicles-weight-limits/
Citations
- N.C.G.S. § 20-118(9)
- N.C.G.S. § 20-118(10)
- Strong's North Carolina Index 3d, Statutes § 5.1
Original opinion text
Requested By: J. G. Wilson, Director, License, Theft & Weight Enforcement, Division of Motor Vehicles
Question: Is a truck equipped with a total of four axles operating with one of the axles (air bag) in a raised position and not carrying any load subject to the penalties prescribed by law if the weight of the truck exceeds the permissible limit for three axles?
Conclusion: Yes.
G.S. 20-118(9) provides, in pertinent part: "The gross weight of any vehicle or combination of vehicles having three axles shall not exceed 47,500 pounds . . ."
G.S. 20-118(10) provides, in pertinent part: "The gross weight of any vehicle or combination of vehicle having four or more axles shall not exceed 64,000 pounds. . . ."
Occasionally a vehicle having four axles, but with only three load bearing axles on the ground, will have a gross weight exceeding 47,500 pounds. The question is whether such a vehicle is in violation of G.S. 20-118(9).
"The intent and spirit of an act are controlling in its construction. In ascertaining this intent the courts should consider the language of the statute, the spirit of the Act and what it sought to accomplish, . . ." Strong's North Carolina Index 3d, Statutes, § 5.1.
It is the opinion of this office that it was the intent of the Legislature that any vehicle having a gross weight exceeding 47,500 pounds must have four or more axles which are load bearing.
RUFUS L. EDMISTEN
Attorney General
Millard R. Rich, Jr.
Deputy Attorney General