Begin Main Content Area

Diesel Idling and Act 124 Information

Pennsylvania Diesel Idling Restrictions - Act 124 of 2008

The Diesel Powered Motor Vehicle Idling Act is available online at the Unofficial Purdon's Pennsylvania Statutes in Title 35, Chapter 23B.

Act 124 expressly authorizes the Secretary of the Department of Environmental Protection to designate employees of the Department to enforce the summary offense provisions of the act. Here is the Employee Designation Letter from the Secretary (PDF).

Act 124 Q & A Documents

Diesel Idling Information

Truck and bus drivers idle their engines during their rest period to provide heat or air conditioning for the sleeper compartment, keep the engine warm during cold weather, and provide electrical power for conveniences such as television. But unnecessary truck idling adversely affects our air quality and wastes fuel. Excess idling can be controlled by changing operating practices and/or installing idle control technologies.

Advanced truck stop electrification provides heat, air conditioning, electricity, internet and phone service and other amenities for an hourly charge.

  • Trucks consume as much as one gallon of fuel per idling hour.
  • Nationally, heavy-duty vehicles use over 1 billion gallons of fuel per year idling, spending almost $2.5 billion.This amounts to about 1 percent of all petroleum imported into the US.
  • Idling produces about 140,000 tons of nitrogen oxides and 7.6 million tons of carbon dioxide annually.

There are strategies and technologies to reduce unnecessary idling including:

Auxiliary power units of various kinds can provide cabin heating, block heating, air conditioning, and electricity so trucks can reduce idling wherever they stop.

  • Management practices
  • Automatic start/stop devices
  • Auxiliary power units, cab heaters, block heaters
  • Shore power with on-board units
  • Advanced truck stop electrification

Click here for EPA's list of specific technologies and vendors. Note that EPA does not certify technologies and that this may not be a comprehensive list. A list of locations that have truck stop electrification available can be found at the following Web site - U.S. DOE Alternative Fuel and Advanced Vehicles Data Center.

Diesel Idling Signs

Who is required to post an approved sign to restrict idling?

Act 124 states that "An owner or operator of a location where subject vehicles load or unload or a location that provides 15 or more parking spaces for subject vehicles shall erect and maintain a permanent sign." Hence, the act requires the location owner or operator to post, at minimum, one sign to alert drivers of subject vehicles of idling requirements. Owners should be forewarned that it is part of the property owner's responsibility to stop idling on their property. Location owners risk fines if illegal idling is occurring on their property. Therefore, signs should be posted in sufficient quantity and positioned so that drivers are alerted to the restrictions placed on idling. There is no maximum number of signs location owners are permitted to post.

Approved PennDOT Idling Restriction Sign Dimensions (PDF)
Follow the link to view Sign R7-100.

Approved PennDOT Sign Manufacturers (PDF)
The list of approved sign fabricators is found in Publication 35 (Bulletin 15) which can be accessed at the link. The list is found in section 1103.04.

Act 124 references 67 Pa. Code 212.101 (a) and (b). Further requirements for signs may be seen in 67 Pa. Code Chapter 212.

Local Regulations

While Act 124 prohibits localities from new idling restrictions, persons subject to the act are still responsible for complying with previously established idling restrictions in the Pittsburgh and Philadelphia regions. See the links below to the local regulations.

Allegheny County Health Department

The ACHD regulation is still on the books but has been determined to be not 'more restrictive than' the provisions of Act 124, relating to Section 9 of Act 124. ACHD will not be enforcing the ACHD regulation and does not have the authority to enforce Act 124. ACHD staff will provide compliance assistance and referrals to PA DEP for enforcement of Act 124.

Ordinance Establishing A Policy On Idling of Diesel Vehicles (PDF)

Regulations for School Bus Idling

Diesel Powered Motor Vehicle Idling (other than school buses) (PDF)
See section 2105.92

Philadelphia County Health Department, Air Management Services

Regulation regarding idling (PDF)

Philadelphia Parking Authority

Parking Authority Idling Ordinance (PDF)


If a citizen believes that a diesel-powered motor vehicle is idling illegally, they may call their nearest DEP Regional Office or their local law enforcement agency. The idling restrictions in Pennsylvania are fixed in statute. Therefore, a local law enforcement officer is able to respond to a complaint about illegal idling. DEP Regional Offices can be reached by calling the statewide Citizen's Complaint Line toll free at 1-866-255-5158. Local law enforcement non-emergency numbers can be found in the local phonebook.


If you have questions regarding Act 124, please contact the Bureau of Air Quality by mail at:

Motor Vehicle Idling Act
PA Dept. of Environmental Protection
Bureau of Air Quality Mobile Sources Section
P.O. Box 8648
Harrisburg, PA 17105-8468

By phone: (717) 787-9495
By email: DEP Air

Learn More