For greener driving, try ‘eco-routing’

When you ask your GPS navigation device for driving directions, it’ll probably suggest the quickest route to your destination. But you could make your trip slightly greener by using a process called “eco-routing” instead — choosing a path that requires less fuel and reduces emissions.

In a study published in Transportation Research Part D, researchers analyzed the costs and benefits of eco-routing. They ran simulations of traffic in downtown Cleveland and Columbus, which include highways, arterials, and smaller local roads. Both are busy urban areas; during rush hour, for example, about 65,000 cars drive through downtown Cleveland per hour.

The team compared two scenarios: one in which all cars take the shortest route and another in which cars take the most eco-friendly route. When eco-routing was used, fuel consumption dropped by 4 to 6 percent and emissions by 3 to 18 percent. The green drivers took longer to reach their destinations though — on average, travel times were about 3 to 5 percent higher.

The results were more variable when the researchers tested specific origins and destinations. In some cases, the eco-route was almost the same as the most time-efficient route, so drivers didn’t save much gas. In another case, the eco-route cut fuel use by 18 percent but took 44 percent longer. The team also found that fuel savings were particularly high when streets were congested.

Overall, eco-routing resulted in about 3 to 9 percent lower fuel consumption compared to traditional navigation, the authors conclude. And the system worked better in Columbus, where downtown streets are laid out in a grid, than in Cleveland’s freeway corridor network. Roberta Kwok | 29 October 2013

Source: Ahn, K. and H.A. Rakha. 2013. Network-wide impacts of eco-routing strategies: A large-scale case study. Transportation Research Part D doi: 10.1016/j.trd.2013.009.006.

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