Dallas County, TX Environmental Rules: Vehicle Idling Restrictions (2026)
Key Facts
- Idling cap
- Five minutes for heavy vehicles
- Weight threshold
- Over 14,000 pounds
- Cold-weather exemption
- Below 40 degrees Fahrenheit
- Authority
- TCEQ 30 TAC 114.512
Summary
Dallas County sits within the Dallas-Fort Worth ozone nonattainment area, where TCEQ Rule 30 TAC 114.512 limits commercial heavy-duty vehicle idling to five minutes. Locally adopted by Dallas County for fleets and contractors.
Sec. 382.0191. IDLING OF MOTOR VEHICLE. (a) In this section, 'idling' means allowing an engine to run while the motor vehicle is not engaged in forward or reverse motion. (b) The commission may not prohibit or limit the idling of any motor vehicle with a gross vehicle weight rating greater than 8,500 pounds that is equipped with a 2008 or subsequent model year heavy-duty diesel engine or liquefied or compressed natural gas engine that has been certified by the United States Environmental Protection Agency or another state environmental agency to emit no more than 30 grams of nitrogen oxides emissions per hour when idling.
Full Breakdown
TCEQ adopted the Texas Locally Enforced Motor Vehicle Idling Limitations rule under 30 TAC Chapter 114, Subchapter J. Dallas County and most DFW counties opted into local enforcement, capping idling at five consecutive minutes for vehicles with gross weight over 14,000 pounds. School buses while loading, emergency vehicles, sleeper berths during federally mandated rest, and vehicles below 40 degrees Fahrenheit are exempt. Enforcement is shared with TCEQ and local police; county fleet contractors must comply. Dallas County does not extend rules to passenger cars.
Violations & Fines
Violations of the TCEQ idling rule are Class C misdemeanors with fines up to 500 dollars per occurrence; repeat fleet violators face TCEQ enforcement orders and contractor disqualification.
Frequently Asked Questions
Does the idling limit apply to my passenger car?
Are school buses exempt?
Sources & Official References
Other rules in Dallas County
Texas rules heatmap·Compare Dallas County to another location·View the Texas environmental rules overview
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