Lane Restriction for Truck Tractors

Oct. 22, 2025, 5:40 a.m.
New Mexico Truck Tractor Lane Restriction Law
Lane Restriction for Truck Tractors

Overview

Effective June 14, 2023, New Mexico Senate Bill 102 (SB 102) created a lane-restriction rule that limits where truck tractors can drive on multi-lane highways.

Key rule:

Truck tractors may not operate in the left lane of a highway with two or more lanes in the same direction, except under limited circumstances.

Legal Reference

  • Statute: New Mexico Statutes Annotated (NMSA) 1978, Section 66-7-317.1

  • Enforced by: New Mexico State Police (NMSP) and local law enforcement

  • Purpose: To improve safety, reduce congestion, and minimize speed differentials between large trucks and passenger vehicles

When a Truck May Use the Left Lane

Truck tractors may enter or remain in the left lane only when:

  1. Passing a slower vehicle traveling in the right lane

  2. Preparing for a left turn at an intersection, private road, or driveway

  3. Responding to an emergency or avoiding an obstacle

  4. Directed by law enforcement or traffic control devices

Once the passing or turn maneuver is complete, the truck must return to the right lane as soon as safely possible.

Penalties

Violating the lane restriction can result in:

  • First Offense: Fine up to $250

  • Second Offense: Fine up to $250

  • Third and Subsequent Offenses: Fine up to $500
    (Each incident may also impact a carrier’s safety record and CSA score.)

Where It Applies

  • Applies to all state and interstate highways in New Mexico with two or more lanes traveling in the same direction.

  • Commonly enforced corridors include:

    • I-40 (from Arizona to Texas)

    • I-10 (southern New Mexico, through Las Cruces)

    • I-25 (north–south through Albuquerque and Santa Fe)

Why the Law Was Passed

  • To reduce congestion caused by slower trucks remaining in the left lane

  • To minimize lane-changing conflicts and improve traffic flow

  • To decrease crash risks, especially on high-volume freight routes like I-40 and I-25

  • To standardize rules with neighboring states such as Texas and Arizona

Impact on Carriers & Drivers

For drivers:

  • Plan lane usage in advance when approaching climbs, exits, or slower traffic.

  • Avoid cruising in the left lane, even briefly, unless passing or preparing to turn.

  • Be aware that NMSP has increased targeted enforcement on major corridors.

For carriers:

  • Update driver handbooks, ELD notes, and route training materials.

  • Reinforce compliance during safety meetings to avoid fines and CSA impacts.

  • Use in-cab alerts or GPS systems to remind drivers in restricted areas.

Industry Perspective

  • Supporters: Say it improves safety and efficiency for all drivers.

  • Critics: Note that in hilly terrain or high-traffic areas, merging back into the right lane quickly can be difficult for heavy trucks.

  • Solution approaches: More signage, pull-outs, and “Truck Lane Ends” notices are being added by the New Mexico DOT.