Saving fuel in over-the-road trucking is relatively easy, because high road speeds and unhindered running make for significant payback from aerodynamics and low-rolling-resistance tires. It’s not so easy in stop-and-go operations, where engine efficiency is inherently low and vehicle inertia must be repeatedly overcome. Drivers in such operations are also more intent on doing their delivery or service-provider jobs, not to mention putting up with traffic and other distractions, than conserving fuel.

UPS is one fleet to look to for a success story in this area. The giant parcel carrier with 90,000 trucks, tractors and package cars around the world is known for its push to adopt alternative fuels and powertrains, which run “green miles,” as the company puts it. However, a large majority of its fleet still runs on diesel and gasoline.

UPS tries to match the vehicle to the needs of the routes, and it’s constantly looking for ways to make its vehicles more fuel efficient regardless of the powertrain. For instance, it worked with Isuzu and Utilimaster to develop lighter-weight composite-body diesel vans that achieved a 40% increase in fuel economy over traditional aluminum vans in testing.

The company plans routes carefully and instructs its drivers to shut off their engines whenever possible.

“The greenest miles are the ones you never run,” David Abney, UPS’s chief operating officer, told an audience at an industry meeting recently.

The company uses computerized route planning and a “smart pick-up” system based on communications with customers to avoid needless miles.

A proprietary system of telematics combines information about the behavioral and mechanical variables that affect fuel efficiency. UPS matches routes to vehicles that get better mileage at the speeds the route requires. Routes are also designed to have the minimum number of stops and starts and still be on time.

Drivers help revise and refine their routes almost constantly. Among the goals: Avoid left turns because they take time and risk collisions with opposing traffic. It’s better to go around the block in a series of quick right turns than wait to make a left turn.

“There was a time when we used to stop everywhere every day, even if there were no pick-ups” from regular customers, says Abney, who began his career as a part-time loader and later worked as a route driver. “Those days are gone.” About 200 million miles are thus saved each year.

A cast-in-stone rule for UPS drivers: Shut off the engine when leaving the truck. Doing this can save fuel, not just during deliveries but also during delays, such as when a long, slow train is blocking a grade crossing, long red traffic lights, and while stopping at the office.

The strict anti-idle policy has cut the amount of time delivery trucks idle by 24 minutes per driver per day, which has led to a fuel savings of $188 per driver in one year.