A few years ago, UPS began planning delivery routes to avoid left turns whenever possible. The idea is to avoid idling while waiting for opposing traffic to pass.
In 2007, UPS reported saving 3.1 million gallons of fuel and avoided 32,000 metric tons of emissions of greenhouse gases. The company presents this information as evidence of its commitment to the environment, but presumably the cost savings were welcome as well.
The delivery company’s policy has been scoffed at and treated as urban myth. But an episode of Mythbusters tested the theory, by sending an ersatz delivery truck into the city streets. First, it took the most direct route, which included a number of left turns. Then, they chose a right-turn-only route. Even though the distance was a bit farther, the right-turn route saved a significant amount of fuel.
The UPS policy may be an offshoot of the “Right Turn on Red” legislation widely adopted during the 1970s. Some western states already permitted drivers to turn right on a red light after stopping to check for traffic. During that era’s energy crisis, research proved that this policy saved up to 4.6 seconds of idling time per stoplight, reducing driving time up to 30% in some circumstances. The policy was widely adopted as a way of promoting fuel efficiency.
Our GPS devices can offer routing that avoids interstates or toll roads. Maybe they should update the software so that we can avoid left turns, following UPS’s lead and taking advantage of the gas savings of turning right.
Web Links
U.S. Department of Energy history of “Turn Right on Red”
http://energy.gov/articles/right-turn-red
Mythbusters episode testing the energy efficiency of avoiding left turns
http://dsc.discovery.com/tv-shows/mythbusters/videos/right-turn-only-minimyth.htm
Photo, taken on June 8, 2010, courtesy of Flickr.