Transport Partnership
U.S. ENVIRONMENTAL PROTECTION AGENCY
Reducing Highway Speed
A Glance at Clean Freight Strategies
Reducing highway speed by 5 miles per hour can cut fuel use and greenhouse gas
emissions by about 7 percent while extending the life of a truck's engine, tires
and brakes. An example is a long-haul truck that reduces its top speed from 65
to 60 miles per hour saves over 1,200 gallons of fuel, cutting its annual fuel bill
by $4,900 while eliminating nearly 13 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. Excessive speed also leads to higher
maintenance costs of 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 pre-
vent 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.
Savings and benefits
Although fuel savings may vary by vehicle and speed range, a combination truck driving 55
miles per hour uses up to 7 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
65 miles per hour to 60 miles per hour could save about $4,900 in annual fuel costs.
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
I A trucking company
interested in saving
fuel and lowering the
cost and frequency of
its equipment mainte-
nance should consider
adopting a speed man-
agement policy, par-
ticularly if its trucks
spend considerable
time on highways.
2 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.
3 When purchasing new
vehicles, a trucking company
may also consider specify-
ing 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 as-
sociations.
SmartWay Transport | EPA^120-F09-042 | www.epa.gov/smartway | 734-214-4767 | smartway_transport@epa.gov
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Reducing Highway Speed
maximum speeds at 60 rather than 70 miles per hour reduces engine wear and extends time between engine re-
builds, saving hundreds of dollars per truck each year while keeping revenue-earning equipment on the road. Fleets
that adopt speed policies report additional savings due to fewer brake jobs 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, and 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 an increase in delivery time
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SmartWay Transport | EPA^120-F09-042 | www.epa.gov/smartway | 734-214-4767 | smartway_transport@epa.gov
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