Md. Code, Transportation § 21-1131
Md. Code, Transportation § 21-1131
in effect(a) Except as provided in subsection (b) of this section, a person may not knowingly or intentionally cause a diesel–powered motor vehicle to discharge clearly visible smoke, soot, or other exhaust emissions onto another person or motor vehicle.
(b) This section does not apply to a person operating:
(1) A diesel–powered vehicle that discharges visible exhaust as the result of normal acceleration or towing;
(2) A commercial vehicle with a gross weight of 10,000 pounds or more; or
(3) A construction vehicle operating at a construction site.
Source: Open US Law by Vaquill AI (CC BY 4.0)URL: https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gtr§ion=21-1131&enactments=falseFetched: 10/17/2026