With constant mobility ingrained in its name and purpose, it's not easy for the Arizona Department of Transportation to cut back on fuel consumption. But with less dollars flowing its way and the high cost of fuel, the agency is looking for ways to use renewable energy to save a buck or two. Right now, Arizona's DOT is testing 37 trucks equipped with solar-powered light bars, according to a news release. Now, DOT drivers can turn their engines off in construction zones and still have warning lights flashing for safety. In addition to taking advantage of the sun, the DOT is also trying to cut down on travel and its associated costs by encouraging videoconferencing and changing work schedules so employees spend less time travelling. Arizona's initiatives are just some of a few that the American Association of State Highway Officials highlighted in a recent release that draws attention to what states are doing to cut down on fuel use.