Studies: Bigger trucks benefit environment

Studies: Bigger trucks benefit environment    Two studies released Thursday claim that increasing tractor-trailers' capacity to haul more goods will reduce greenhouse gas emissions.
   The American Transportation Research Institute, the research arm of the American Trucking Associations (ATA), said a comparison of trucks operating with a gross vehicle weight of 100,000 pounds in Maine improved fuel efficiency 14 percent to 21 percent when operating on an interstate route instead of a state highway. Trip emissions were estimated to decease 6 percent to 11 percent for carbon dioxide and 3 percent to 8 percent for nitrogen oxide and particulates.
   The national limit for loaded trucks is 80,000 pounds, but Maine has a federal exemption to run heavier trucks on Interstate 95 and the Maine Turnpike to support the logging industry. States can set their own limits on state highway systems.
   ATRI conducted the study for the Maine Department of Transportation. State officials are seeking a broader exemption or new legislation that would raise the allowable weight level to 97,000 pounds. One of the ATA's policy goals is to allow states the option to raise the weight limit to 97,000 pounds on federally designated highways.
   Using simulation modeling, ATRI said it also found that heavier trucks that traveled a slightly longer route with higher average speeds consumed less fuel and had fewer emissions than traveling a route with lower average speeds, numerous speed limit changes and traffic signals.
   'This research quantifies how the mutual goals of resource conservation and emission reductions could be advanced by allowing Maine to apply state weight laws to its Interstate highways,' said Mike Card, president of Combined Transport Inc., and a member of ATRI's board of directors, in a statement.
   Although the study compares fuel and emission outcomes for different routes, it didn't compare the differences between an 80,000-pound and 100,000-pound truck.
   A second study by the Northeast States Center for a Clean Air Future (NESCCAF) and the International Council on Clean Transportation said greenhouse gas emissions from trucks can be reduced up to 40 percent starting in 2017 with new and available technology and that increasing vehicle size and weight could cut truck fuel consumption and emissions by an additional 10 percent.
   Fuel consumption could be cut 20 percent by 2012 with existing technology and process improvements. Many truckers have not adopted existing technologies because of the high investment cost.
   NESCCAF is a collaborative institution of air pollution control officials in Northeastern states from Maine to New Jersey.
   Researchers noted that only 55 percent of a truck's fuel energy is converted into power, while another 19 percent of energy is lost to wind resistance, and other energy losses stem from the transmission, tire resistance and idling.
   Class 8 trucks average about 6 miles per gallon and that is expected to rise to 6.8 mpg by 2015, according to the Energy Department.
   The study estimated that 8 billion gallons of diesel fuel and 97 million tons of carbon emissions could be saved annually by technological and operational measures.
   The report can be found at here. ' Eric Kulisch