The latest push for regulations out of Washington focuses squarely on the gas gauges of transportation vehicles. A congressionally-mandated report from the National Research Council is recommending new approaches that federal agencies could use to regulate the fuel consumption of medium- and heavy-duty vehicles, such as tractor-trailers, transit buses and work trucks. Currently there are no fuel consumption standards for such vehicles, which account for about 26% of the transportation fuel used in the U.S.
"The choices that will be made over the course of the next few years will establish the regulatory design for medium- and heavy-duty vehicle fuel consumption standards for the next several decades," says Andrew Brown Jr., chair of the committee that wrote the report and chief technologist at Tier 1 automotive supplier Delphi Corp. The report also evaluates various technologies and methods that could improve the fuel economy of these vehicles.
In 2007 Congress passed legislation requiring the U.S. Department of Transportation for the first time in history to establish fuel economy standards for medium- and heavy-duty vehicles. The National Highway Traffic Safety Administration (NHTSA) asked the National Research Council to recommend the best ways to measure and regulate fuel economy for these vehicles, and assess technologies that could improve it.
Advanced diesel engines in tractor-trailors could lower fuel consumption by up to 20% by 2020, according to a study by the National Research Council.
The report also estimates the costs and maximum fuel savings that could be achieved for each type of vehicle by 2020 if a combination of technologies were used. The best cost-benefit ratio was offered by tractor-trailers, whose fuel use could be cut by about 50% for about $84,600 per truck; the improvements would be cost-effective over ten years provided gas prices are at least $1.10 per gallon. The fuel use of motor coaches could be lowered by 32% for an estimated $36,350 per bus, which would be cost-effective if the price of fuel is $1.70 per gallon or higher. For other vehicle classes, the financial investments in making improvements would be cost-effective at higher prices of fuel.
"Our committee also recommends that NHTSA conduct a pilot program to test drive the certification process and validate the regulatory framework."
Instead, any regulation of medium- and heavy-duty vehicles should use a metric that reflects the efficiency with which a vehicle moves goods or passengers, such as gallons per ton-mile, a unit that reflects the amount of fuel a vehicle would use to carry a ton of goods one mile. This is called load-specific fuel consumption.
The report does not recommend a specific numerical standard because NHTSA will need to establish standards tied to the task associated with a particular type of vehicle; garbage trucks might be held to a different standard than transit buses, for example. NHTSA should base its regulations on national data on the average payload carried by each type of vehicle. The agency should regulate the final-stage vehicle manufacturers rather than component makers, as the former has the greatest control over the vehicle's design, the report adds.
"Our committee also recommends that NHTSA conduct a pilot program to test drive the certification process and validate the regulatory framework," Brown says.
While regulating medium- and heavy-duty vehicles will be more complicated than it is for passenger cars because of the variety of vehicles and their differing tasks and terrains, the barriers are not insurmountable, the report says. Japan regulates the fuel economy of these vehicles, and both the European Union and the state of California are developing standards.
However, one way to avoid the complexity of regulating different types of vehicles would be to impose a fuel tax, which would induce companies to optimize the fuel-efficiency of their operations. The report urges Congress to consider this approach. Another alternative approach -- applying a cap-and-trade system to trucking companies similar to the one that Congress is considering as a way to lower CO2 emissions -- would similarly provide these companies with an incentive to adopt fuel-saving technologies and operational methods.