^SmartWay5
     Transport Partnership
     U.S. ENVIRONMENTAL PROTECTION AGENCY
                               A Glance  at
            Clean Freight Strategies
Reducing  Highway Speed
  Reducing highway speed by five miles per hour can cut fuel use and greenhouse gas emissions by over seven
  percent while extending the life of a truck's engine, tires and brakes. A long-haul truck with 90 percent highway
  operation that reduces its top speed from 70 to 65 miles per hour could cut its annual fuel bill by $1,450 while
  eliminating nearly ten metric tons of greenhouse gas reductions.
  What is the challenge?
  A typical combination truck spends 65 percent or
  more of its operating time at highway speeds. Line-
  haul trucks spend even more time on highways. The
  impact of speed on fuel economy depends upon
  many factors including vehicle aerodynamics, engine
  speed and operating conditions. As a general rule of
  thumb,  increasing  speed  by one  mile  per hour
  reduces fuel economy by about 0.1  miles per gallon.
  For a truck with poor aerodynamics, the fuel penalty
  may be nearly twice as great. Higher speed also
  leads to higher maintenance costs  by increasing
  wear on the engine, tires and brakes.

  What is the solution?
  Speed management is an easy and effective way to
  save fuel, reduce emissions,  and prevent  excess
  wear. A trucking firm or driver can adopt a speed
  policy at little or no cost. The most successful speed
  management policies  combine technology (e.g.,
  speed  settings on electronic engine controls) with
  driver training and incentive programs to encourage
  drivers to maintain speed limits.  Most new truck
  engines are electronically controlled so the  cost of
  changing maximum speed settings on these engines
  is negligible.


  The results are in ...
  Although fuel savings may vary by vehicle and speed
  range, a national trucking association estimates that
  a combination truck driving 55 miles per hour uses up
  to 20 percent less fuel than a similar truck  driving 65
  miles per hour. Other analyses indicate that reducing
  the maximum speed of a typical long-haul truck from
  70 miles per hour to 65 miles per hour could save
  about $1,450 in annual fuel costs.  Reducing  the
  maximum speed to 60 miles per hour could save an
  additional $1,850,  bringing the estimated  annual
  savings to $3,300.

  Reducing speed can cut truck maintenance costs
  and  reduce the frequency of maintenance work. The
  time between  engine  overhauls,  for example, is
  directly related to fuel use. Holding maximum speeds
  at 60 rather than 70 miles per hour reduces  engine
      wear and extends time between engine rebuilds,
      saving hundreds of dollars per truck each year while
      keeping revenue-earning equipment on the road.
      Fleets that adopt speed policies report added savings
      due to fewer brake replacements and other service
      work.

      Reducing highway speed does increase travel time.
      Assuming ideal conditions, a trucker driving 60 miles
      per hour instead of 65 miles per hour could spend
      about eight  percent longer on  the road. Of course,
      the time difference may be less, depending upon
      road conditions, weather, traffic congestion, and road
      construction. If a trucking company pays its drivers
      by the mile  or by the load rather than by the hour,
      reducing speed should  not increase labor costs. It
      could reduce the productivity of trucking operations
      since slower trucks may carry fewer loads. However,
      the benefits of lower fuel  and maintenance costs
      combined with less frequent out-of-service work and
      driver safety considerations may well outweigh any
      costs associated with increased delivery time.


      Next steps
      A trucking company interested in saving fuel  and
      lowering the cost and frequency of its equipment
      maintenance should  consider adopting a  speed
      management policy, particularly if its trucks spend
      considerable time on highways. A number of well-
      managed truck fleets have programs in place to
      reduce highway speed and promote safe driving by
      using   driver  training,  incentive  programs  and
      electronic engine controls. A trucking fleet interested
      in  following these examples  may learn more by
      reading articles and fleet profiles in truck industry
      publications. When purchasing new vehicles,  a
      trucking company may also  consider  specifying
      equipment designed to optimize truck performance at
      lower maximum speeds. Trucking companies  and
      drivers  interested in learning more about the effects
      of speed on fuel economy may contact truck and
      equipment manufacturers or their state and national
      trucking associations.
U.S. Environmental Protection Agency £ Office of Transpor
  February 2004. EPA420-F-04-007. ^ For more information,, visit: www.epa.gov/smartway

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