Summary of State Anti-Idling Regulations 

State Citation Applicability Idling Time Limit Exemptions 

Source: California Air Resources Board and EPA

AZ AZ ST § 11-876 Heavy duty diesel

vehciles >14,000 lbs.

5 minutes • Emergency vehicles

• Traffic conditions• Need for driver to sleep in vehicl• Necessary for equipment (refriger

CA CA HLTH & S 

§ 40720

Marine terminals orports processing100,000+containers/year

30 minutes • Acts of God

• Strikes• State/Federal emergencies• Unavoidable/unforseeable event

CO(Denver)

Denver MunicipalCode Sec. 4-43

Any motor vehicle 10 minutes in any one hour • Ambient temperature <20o F for

previous 24 hours• Ambient temperature <10o F• Emergency vehicles• Traffic conditions• Vehicle is being repaired/serviced• Take-off power for auxiliary uses• Vehicles engaged in traffic opera

CT Sec. 22a-174-18(a)(5) Mobile source engine 3 consecutive minutes • Traffic conditions

• Mechanical difficulties• Heating/cooling when necessary• Bring engine to OEM recommendoperating temperature• Ambient temperature <20o F• Vehicle is being repaired/serviced• Aircraft, locomotives, marine veslawnmowers, snow blowers, and smhome appliances
State Citation Applicability Idling Time Limit Exemptions 

Source: California Air Resources Board and EPA 2

CT Non regulatory school

bus policy

School buses Shut off engine immediately

unless leaving within 3minutes; AM start-up idlingrestricted to timerecommended to reachengine operatingtemperature or defrostwindows

• To operate safety equipment• To maintain safe temperature forchildren with special needs• Ambient temperature <20o F

HI § 11-60.1-34 All motor vehicles No specified time • Vehicle is being repaired/serviced

• Necessary for auxiliary equipmenonto vehicle• Loading/unloading passengers - nexceed 3 minutes• Build up op pressure/cooling dowengine - not to exceed 3 minutes

MD § 22-402 Motor vehicles 5 minutes • Traffic conditions

• Mechanical difficulties• Necessary for auxiliary equipmeninstalled on vehicle• To bring vehicle up to OEM’srecommended engine operatingtemperature

DC Title 20, Reg 900.1 Diesel/gasoline

vehicles

3 minutes • Necessary for auxiliary equipmen

installed on vehicle• To operate AC for 15 minutes on with 12 or more people• To operate heating equipment whtemperature is <32o F

MA Chapter 90, Sec. 16A Motor vehicles 5 minutes • Vehicle is being repaired /service

• Delivery vehicles in which enginepower is necessary• Vehicles in operation for whichassociate power need is required
State Citation Applicability Idling Time Limit Exemptions 

Source: California Air Resources Board and EPA 3

MN § 123B.885 Diesel school buses N/A (must minimize to

extent practical the idling ofschool bus engines)

None 

MN (St.Cloud)

Section 706 Motor vehicles

(within specified 2block area of city)

5 minutes N/A 

MO (St.Louis)

Ordinance 64749D Motor vehicles 10 minutes • Emergency vehicles 

MT (Lewis& Clarkcounty)

Rule 3.101 Diesel or locomotive

engine operatingwhen healthdepartment declaresair quality is poor

2 hours in any 12 hourperiod

• When a Board of Health variance granted

NV NAC 445B.576 Diesel truck or bus 15 minutes • When a variance is issued

• Emergency vehicles• Removal of snow• Used to repair or maintain othervehicles• Traffic conditions• During repair/maintenance• Emission is treated and contained method approved by commission• Engine must idle to perform a spetask (e.g., drilling)

NH Env-A 1101.05 Diesel/gasoline

vehicle

5 minutes >32o F

15 minutes >-10o F & <32o F

No limit <-10o F and no

nuisance created

• Traffic conditions• Emergency vehicles• Takeoff power for auxiliary uses• Vehicle is being repaired/serviced• Operated solely to defrost windsh
State Citation Applicability Idling Time Limit Exemptions 

Source: California Air Resources Board and EPA 4

NJ 7:27-14.2 Diesel powered

motor vehicles

3 minutes30 minutes for permanentvehicle at business15 minutes for vehiclestopped for >= 3 hours

• Emergency vehicles in an emergesituation• Emergency vehicle of GVWR >1lbs transporting property on public • Diesel bus while loading/unloadin• Traffic conditions• When auxiliary power is needed fother equipment or climate control• Being inspected by State/Federalinspector• Vehicle is being repaired/serviced• Detach/exchange trailer• Light duty diesel vehicles

NY § 217-3.2, 3.3 Diesel bus or truck 5 minutes • Traffic conditions

• If regulation already exists to maiconditions for passenger comfort• During maintenance• To provide power for auxiliary pu• Emergency vehicles• Mining/quarrying on own propert• Temperature <25o F if motionless 

hours• Diesel waiting to undergo a roadsemission inspection• Hybrid electric engine chargingbatteries

NY (NYC) NYC Code § 24-163 Motor vehicles 3 minutes • Emergency motor vehicles

• Loading/unloading• Temperature <40o F

PA 52 P.S. & 701-223-A Diesel powered

equipment

N/A None 
State Citation Applicability Idling Time Limit Exemptions 

Source: California Air Resources Board and EPA 5

PA (Philad.) Reg. IX Heavy duty diesel

vehicles >8,500 lbs,or passenger carryingcapacity >12 

2 minutes0 minutes for layovers5 minutes <32o F

20 minutes <20o F

20 minutes for buses withAC and non-openablewindows and >75o F

None 

TX(Houston/Galveston)

Sec 114.500-114.509 Diesel/gasoline motor

vehicles GVWR>14,000 lbs

5 minutes April 1 - Oct 3130 minutes for heat/AC fortransit and school buses

• Traffic conditions• Vehicle is being repaired/serviced• Solely to defrost windshield• Power source necessary for mechoperation other than propulsion• Airport ground service equipmen• Emergency vehicles• Owner of vehicle rented or leased another who is not employed by thowner

UT (SaltLake City)

Health Dept. Reg.#28.6.8

Diesel vehicles 15 minutes • Supply power to a refrigeration u

• Supply heat/AC to sleeper cab• Emergency vehicles

VA § 46.2-1224.1, 9 VAC

5-40-5670B&C

Buses whenunattended, parked,or stopped

10 minutes • Traffic conditions

• Vehicle is being repaired/serviced• School buses• Public transit buses