Heavy duty vehicles have very different driving patterns from smaller passenger cars and trucks. Most heavy duty vehicles are transporting goods or riders and are being operated for extended periods of time. In contrast passenger cars are being used for shorter term trips such as commuting or shopping. When not in transit, heavy duty vehicles are either loading or unloading their contents or preparing to head back out on the road again. Rather than shut off their engines, drivers often leave these vehicles running, or idling.

There are a number of reasons heavy duty vehicle operators choose to idle their engines. Idling provides heat or air conditioning inside the vehicle for driver comfort, it keeps the engine and fuel warm during cool weather, and it provides electrical power for onboard applications. This latter point is of particular concern for trucks that are transporting products that must be contained in refrigerated units. Additional reasons for idling include personal safety and basic driver habit.

Long-haul truck drivers have another concern. These vehicles are the heart of the country's shipping and delivery system for goods. According to the U.S. Environmental Protection Agency, the majority of all goods are carried aboard freight trucks for a total of 4.5 trillion vehicle miles traveled. A single truck can average 500 miles of driving each day and can be on the job for as many as 26 days in a given month. Drivers typically drive for set number of hours a day before pulling off to a truck stop for an extended period of rest. During this time the truck remains idling for many of the reasons stated above, but comfort and safety concerns are amplified as the drivers sleep inside their trucks. On average truck drivers spend between 1,800 to 2,400 hours a year idling.

An estimated one gallon of diesel fuel is consumed for every hour a vehicle is at idle. This amounts to about 1 billion gallons of diesel fuel lost as a result of idling. Moreover, 11 million tons of carbon dioxide and 150,000 tons of smog-forming nitrogen oxides are collectively emitted each year. The fuel lost during idling contributes to America's dependency on oil, the majority of which is imported and represents an annual economic cost of about $1.8 billion.

In contrast to other Philadelphia Diesel Different options, anti-idling or idle reduction strategies do not deal directly with emissions, but focus instead on fuel conservation. While there are certainly relevant technologies that can be used, anti-idling can be accomplished simply through behavioral changes by the drivers. There are three major types of fleets that are obvious candidates for education on idle reduction strategies: trucks, buses and trains.

Idle Reduction Technologies

Idle Reduction Technologies (IRTs) refer to actual devices that obviate the need for idling by providing the driver interior comforts without running the engines. IRTs can be placed in the heavy duty vehicles themselves or can be provided at truck stop locations.

Mobile Technologies

Direct-Fired Heaters
are stand-alone units capable of providing heat to vehicles in cold weather. They cost about $1,000 to $2,000. Unfortunately, they do not provide for other driver needs, like air conditioning. Automatic Engine Idle devices actually shut off engines when not being used, while still providing needed air conditioning or heating. These also cost about $1,000 to $2,000. Lastly, Auxiliary Power Units (APUs) are small electric generators. They are more expensive, costing anywhere from $5,000 to $7,000 and limiting the carrying load of the vehicle because of their weight.

Stationary Technologies

Truck Stop Electrification (TSE)
refers to truck stops that have the ability to provide power to trucks so that drivers can meet all their needs without having to run their engines. Shore Power TSE requires trucks to be specifically modified to be able to accept electricity transmitted at the truck stop. The cost is about $2,500 per truck parking space to provide the electricity and another $2,500 to modify the truck so that it can receive the electricity. Advanced or Rental TSE can provide the electricity to practically any truck with little modification required. The cost of installing the system is about $10,000 per parking space. For both types of TSEs there is also an operating fee while using the electricity of about $1.00 to $1.50 an hour.

The U.S. Environmental Protection Agency and the U.S. Department of Transportation Federal Highway Administration have established a list of ideal truck stop candidates for idle reduction projects along the I-95 Corridor. Pennsylvania has two locations, both within the Greater Philadelphia region on this list: Walt Whitman Truck Stop and Bensalem Travel Plaza. Jump HERE (.doc) to see the full list.

Idle Reduction Policies

As noted before, idle reduction is a conservation measure. Thus, it can be accomplished as a matter of company or school district policy. While, some idling needs have to do with driver comfort (i.e., keeping a truck cab or a bus warm during the winter and cool during the summer), some of the idling is strictly a matter of habit. The driver just does not feel like turning off the engine since he or she will soon have to start it up again. It is in cases such as these that Idle Reduction Policies, supported by driver education, can work. Philadelphia Diesel Difference supports organizations voluntarily establishing an Idle Reduction Policy as an inexpensive, easy way to reduce diesel emissions and save fuel.

Anti-Idling Laws

If voluntary idle reduction policies are not adequate, a community can mandate anti-idling by law in order to protect public health. Philadelphia has an anti-idling ordinance enforced by its Air Management Services. Regulation IX prohibits idling for more than two minutes of a heavy-duty diesel powered motor vehicle before, during, or in between trips, unless it is necessary to attain normal operating conditions or if the ambient temperature is uncomfortably high or low. Go HERE for more information. Philadelphia also has an anti-idling ordinance in its Traffic Code enforced by the Parking Authority. Section 12-1127(3) of the Philadelphia Code prohibits bus or truck idling for longer than five minutes unless the temperature is 40 degrees Fahrenheit or less, idling is due to traffic congestion, or idling is necessitated by law to ensure bus passenger comfort. Jump HERE for more information.

On February 6, 2009, Pennsylvania's anti-idling law (the Diesel-Powered Motor Vehicle Idling Act) took effect. It limits bus and truck idling to five consecutive minutes in any continuous 60-minute period, although there are exclusions to the requirement. Jump HERE to find the bill.

California Air Resources Board has put together a helpful chart (pdf) listing local and state anti-idling laws across the country.


U.S. Environmental Protection Agency's Idle Reduction Page

National Transportation Idle Free Corridors (Joint U.S. Environmental Protection Agency and U.S. Department of Transportation Federal Highway Administration Page)