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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Public Roads - March/April 2005

March/April 2005
Issue No:
Vol. 68 No. 5
Publication Number:
Table of Contents

Financing Idle-Reduction Projects

by Diane Turchetta

New technologies offer cost-effective strategies to limit air emissions at truckstops.

Long-haul trucks like this one represent a significant percentage of mobile source emissions of air pollutants. Technologies to reduce truck idling can help.

For long-haul truckers, their trucks not only serve as their offices but also represent homes away from home. After a long day—or night—of driving, truckers often pull off the highway into truckstops to rest, sleep, eat, or even check e-mail or watch television in their cabs. To maintain a comfortable temperature in the cab and power small electrical devices like televisions, microwaves, and refrigerators, truckers typically keep their engines running, or idling. Idling, however, releases harmful air emissions and wastes a significant amount of fuel, creating a financial burden for the trucking industry.

Over the last several years, Federal and State agencies, and the trucking industry as well, have increasingly looked for alternatives to idling as a means to reduce emissions from heavy-duty trucks, conserve energy, and save money in fuel costs. In May 2001, the Bush administration's Federal energy plan, National Energy Policy: Report of the National Energy Policy Development Group, directed the U.S. Environmental Protection Agency (EPA) and U.S. Department of Transportation (USDOT) to address the issue of idling emissions from long-haul trucks.

In response, EPA and USDOT partnered with the U.S. Department of Energy (DOE) and expanded the scope to reduce idling from all heavy-duty diesel engines including locomotives, marine vessels, buses, aircraft, and off-road equipment. In 2004, the three agencies conducted several regional workshops on idling reduction and held a national conference on the subject in May 2004.

Among the commercially available solutions for heavy-duty trucks are several onboard and external technologies that can provide power without requiring the engine to run. By installing one or more of these solutions in trucks or at truckstops, States, metropolitan planning organizations (MPOs), and local governments can help reduce their mobile source air emissions and maintain or achieve compliance with air quality regulations. And, with funding available from the USDOT Congestion Mitigation and Air Quality Improvement (CMAQ) program and other Federal and State sources, agencies can get the job done cost effectively.

A truck driver accesses the Internet using a high-speed computer integrated with the window adapter of a shorepower electrification system. This model also provides drivers with filtered heat and air conditioning, phone service, satellite television, electrical outlets, and movies on demand.

Defining the Problem

EPA defines two types of idling. The first, considered unavoidable, includes waiting at traffic lights or sitting in congestion on highways or during emergencies. The second is termed avoidable and includes times when truck drivers idle for cab comfort—air conditioning in the summer and heat in the winter—or to operate onboard auxiliaries such as televisions and computers. This second type is the focus of current Federal efforts to reduce idling.

Several factors drive the recent focus on finding alternatives to idling. One is the potential for significant energy savings. EPA estimates that approximately 500,000 to 1 million long-haul trucks are in operation today, each idling anywhere from 1,800 to 2,400 hours per year. EPA data have shown that a long-haul truck at idle for 1 hour burns approximately 3.8 liters (1 gallon) of diesel fuel. Cumulatively, idling wastes as much as 3.78 billion liters (1 billion gallons) of fuel per year.

Another important reason is to reduce criteria air pollutants, carbon dioxide emissions, and toxic air emissions--an emerging issue for the transportation community in general and many metropolitan areas in particular. The resulting emissions related to truck idling include 163,000 metric tons (180,000 tons) of nitrogen oxides (NOx), 4,535 metric tons (5,000 tons) of particulate matter (PM), and 9.98 million metric tons (11 million tons) of carbon dioxide (CO2) per year.

This generator is mounted on Darren and Lisa King's truck. "[It]" keeps us warm or cool wherever we travel, and the fuel savings are significant, " says Darren King. "We will achieve payback of our costs in about a year."

In 2004, EPA issued designations for new ozone nonattainment areas and for fine particulate matter. The new ozone designations add 126 areas around the country to EPA's list of ozone nonattainment areas. Idle-reduction projects may be a useful strategy in the toolbox that States and MPOs can use to meet the National Ambient Air Quality Standards.

Other adverse impacts of idling include noise, increased engine maintenance costs, and adverse impacts on driver health and safety.

Assessing the Pros and Cons of Idle-Reduction Technologies
Cost Pros Cons
Onboard Engine Control Module $0 No extra cost
Available from engine manufacturer
Does not address cab comfort
Automatic Shutdown/Turn-On System <$1,000 Low cost
Available from engine manufacturer
Low driver acceptance
Direct-Fired Heaters $900–$1,200 Low cost Lightweight
Available from engine manufacturer
Heat only
Auxiliary Power Units/Generator Sets $5,000–$7,000 Provides all needs Expensive, heavy, noisy, maintenance
Requires after-market retrofit
Battery Powered Heating/AC $7,000–$8,000 Provides all needs
Zero air emissions
External (Offboard) Electrified Parking Spaces –RV Model $6,000 per space Lower cost Requires modifications to truck (electric heat/AC, inverter/charger)
Electrified Parking Spaces –All Inclusive $18,000 per space No truck modifications needed Very expensive
Source: EPA

A Variety of Solutions

Behavioral change is the simplest solution. Informing drivers and operators about the fuel consumption, emissions, and potential health risks plays an important part in changing behavior. On the technology front, the alternatives to idling fall into two categories: onboard and offboard (external) technologies. The onboard solutions consist of direct-fired heaters, auxiliary power units (APUs), automatic engine shutdown/startup systems, and battery-powered systems. Although each of these technologies offers a viable alternative to idling, cost and weight are among the factors that drivers and trucking companies need to consider when selecting a solution.

Direct-fired heaters are small, lightweight devices usually installed in the tool or luggage compartment. They provide heat only. APU's are small, 3.7- to 7.5-kilowatt (5- to 10-horsepower) diesel-powered generators installed on the truck to provide air conditioning, heat, and electrical power to run appliances. An automatic engine shutdown/startup system controls the engine (start and stop) based on a set time period or on ambient temperature, and other parameters (such as battery charge). Finally, the battery-powered systems provide air conditioning and heat using a battery pack to supply the power. The battery pack is usually installed under the bunk bed in the sleeper compartment and can provide 8 to 10 hours of power depending on the capacity and voltage of the batteries. One new battery technology system, which will heat and cool the cab for more than 10 hours, has built-in components that will replace the need for several factory components, such as the underbunk heating, ventilation, and air-conditioning (HVAC) system, the standard battery box, and the starting batteries, thereby eliminating some of the weight issues related to the use of battery-powered systems.

The external technologies consist of two types of electrification systems. The first, shore power, takes its name from the process used to supply electricity to mobile users at marinas and recreational vehicle parks. At a truckstop, the driver would run an outdoor extension cord from the electricity source to the truck to maintain cabin comfort and power any appliances. This option requires modifying the truck's engine to facilitate plugging in the electrical connection points.

The other external technology is known as a truckstop electrification (TSE) system or electrified parking space. After pulling into a space, the driver rolls down the window and inserts a plastic template that is connected by a hose to an overhead truss equipped with an HVAC system and electrical power. The TSE system requires no modification to the truck.

Both onboard and external options result in significant reductions in NOx, PM, and CO2 emissions. The Knoxville Regional Transportation Planning Organization, for example, is investing $2 million in CMAQ funds in projects to install electrification units at truck stops throughout Knox County, TN. According to Director Jeff Welch, the organization plans to install 200 units over the next 2 years, the first half of which have been in operation for about a year.

Direct-fire heaters like this one typically are mounted in the tool compartment under the bunk of trucks with sleeper cabs, where they can heat the cab and/or bunk. The diagram (inset) shows the components of AIRTRONIC D2, direct-fired heater that operates on gasoline or diesel fuel.

"Three interstates converge in our area, and 60 percent of emissions from mobile sources come from heavy-diesel trucks," Welch says. "From our perspective, the TSE units represent an important opportunity for us to minimize emissions. In fact, as of October 2004, the units at Watt Road and I–40 have eliminated 3,400 metric tons [3,750 tons] of emissions."

Welch adds that the rising prices for diesel fuel may encourage more people in the industry to embrace this and other strategies to reduce idling, especially because they offer significant economic benefits. "An idling truck uses about 1 gallon of diesel fuel per hour," he says. "At $2 or more per gallon, the costs add up quickly. The price for a trucker to rent a TSE unit, however, is about $1.25 to $1.50 per hour. For communities with anti-idling legislation, this technology provides a real service to truckers."

Emission Credits

In addition to improving air quality, State DOTs and MPOs also are interested in implementing idle-reduction projects because of the resulting emissions reduction credits.

In January 2004, EPA issued guidance that provided a methodology for how to calculate emission reduction credits from idling truck emissions for use in State Implementation Plans and the transportation conformity process. Guidance for Quantifying and Using Long Duration Truck Idling Emission Reductions in State Implementation Plans and Transportation Conformity is available online at

The South East Texas Regional Planning Commission, an MPO in Beaumont, TX, recently used the guidance to help the region emerge from a conformity lapse that could have waylaid numerous highway projects. The MPO found itself in noncompliance for NOx emissions and began searching for solutions to help reduce its emissions. Upon learning about truckstop electrification, the commission included a TSE project as a major component of its strategy to reduce NOx emissions.

The MPO determined that the project could reduce NOx emissions by 2.7 kilograms (6 pounds) per day, which enabled the region to pass its 2005 conformity determination. "The technology came along at a great time," says Bob Dickinson, director of the transportation and environmental resources department with the South East Texas Regional Planning Commission. "We needed to show a fairly large reduction in NOx emissions, and this project became an important strategy to use in our metropolitan transportation plan."

Dickinson adds that in addition to reduced air emissions, idle-reduction technologies also offer driver health and traffic safety benefits: "When a driver comes into a truckstop, the electrification unit enables him or her to shut down the engine, eliminating the smell, fumes, and vibration associated with an idling truck. The driver can sleep more comfortably and be more relaxed, which means he or she will be refreshed and alert before getting back on the road."

Funding for Idle-Reduction Projects

USDOT, EPA, and DOE all offer Federal sources of funding for idle-reduction projects. The CMAQ program has been the largest source of support. To date, CMAQ has funded numerous electrification projects (in operation or pending in the application process) around the country at a cost of approximately $15 million to $17 million.

A simple, $10 window adaptor makes this electrification system compatible with many makes and models of long-haul trucks. Here, a row of trucks use the system at the Petro Stopping Center in Knoxville, TN.

The CMAQ program was established to fund projects and programs that reduce transportation-related congestion and emissions in nonattainment and maintenance areas. Since the beginning of the program, CMAQ has funded approximately 15,000 projects at a total cost of $13 billion.

The administration proposed reauthorizing the program in the new bill for transportation funding, the Safe, Accountable, Flexible, and Efficient Transportation Equity Act (SAFETEA), at $8.9 billion over the 6-year life of the bill.

One of USDOT's innovative financing programs, the State Infrastructure Bank (SIB), also has provided funding for idling-reduction projects. An SIB is a State-directed program that enables States to borrow funds for eligible Federal-aid projects. The State receives repayments over time that can be directed toward other transportation projects. New York State, for example, successfully secured funding from its SIB to provide some of the capital needed to finance two truckstop electrification projects along the New York State Thruway.

Section 129 loans (named for Section 129 of Title 23 of the United States Code) are a similar USDOT innovative financing program, which also can be used to fund idle-reduction projects. Through Section 129, States can use Federal-aid funding to make loans to private or public entities. The loans must be repaid within a 30-year period, but smaller activities like idling-reduction projects could have a shorter repayment period, which means that States will be reimbursed quickly (with interest) so they can fund more projects.

At the State level, programs such as California's Carl Moyer Memorial Air Quality Standards Attainment Program and the Texas Emissions Reduction Plan also provide financial assistance. State agencies, such as the New York State Energy Research and Development Authority--a pioneer in the field of idle reduction--and the Sacramento Municipal Utility District, also have funded numerous projects. The funding has supported projects for both onboard and external technologies.

Battery packs like this one install conveniently under the sleeper in truck cabs (left). This air conditioning and heating unit is affixed to the back of a shuttle bus (right).

A leading manufacturer of idling-reduction equipment currently has a pending loan application on file with USDOT's Transportation Infrastructure Finance and Innovation Act program. If approved, USDOT would lend the company approximately $300 million to deploy TSE infrastructure at truckstops around the country.

Finally, another alternative for funding might be a public-private partnership. Because several of the CMAQ-funded projects were financed through public-private partnerships, idle-reduction projects also may consider this type of stakeholder collaboration as a potential option for funding as well.

For more information on USDOT's innovative finance programs, visit finance/index.htm.

A group inspects the shorepower electrification system at Wilton Travel Plaza, off I-87 in Wilton, NY. A yellow cable runs from the shorepower kiosk to the cab of the truck (left). A driver inserts his user card into the payment console on the kiosk (right).


Reducing the amount of time an engine idles can help improve the air quality at truckstops, borders, warehouses, construction sites, ports, airports, and rail yards. Projects to reduce truck idling represent one strategy that nonattainment areas around the country should consider implementing to help achieve National Ambient Air Quality Standards. Other strategies to control mobile source emissions include inspection and maintenance programs; use of reformulated, alternative, and ultra low-sulfur diesel fuels; and vehicle technology strategies, such as the use of particulate matter filters and diesel oxidation catalysts.

Officials at USDOT, EPA, and DOE continue to work with stakeholders to educate them on the benefits of idle reduction, while also identifying funding opportunities and providing technical assistance in the implementation and deployment of projects. Representatives from the three agencies currently are working on a national strategy to help accelerate the deployment of idle-reduction projects around the country.

At this point, the role of the Federal government has focused on deploying idle-reduction technologies to encourage market penetration, thereby making existing technologies more affordable, and research and development in an effort to identify technologies for the future.

"The future for idle-reduction activities looks bright," says Associate Administrator Cindy Burbank for FHWA's Office of Planning, Environment, and Realty. "Although the emission reductions that result from individual idle-reduction projects are small compared to the total emissions in a nonattainment area, for some areas, especially those on the margins of nonattainment, idling-reduction measures could be the ticket to achieving tomorrow's air quality success stories."

Diane Turchetta is an environmental protection specialist in the FHWA Office of Planning, Environment, and Realty, where she primarily works on transportation-related air quality issues including climate change, energy use, and alternative fuels. She holds a bachelor's of science in public administration from the Pennsylvania State University and a master's in public administration from Virginia Polytechnic Institute and State University. Before joining USDOT, Turchetta worked at EPA on fuel-related issues and served as national program manager for the oxygenated fuels program.

For more information, visit or contact Diane Turchetta at 202–493–0158 or