Highlands County, Florida, opened the state’s first-ever landfill-gas-powered asphalt plant in 2008. The plant burns the methane gas produced by the landfill to heat the aggregate to make the asphalt that will pave the county’s roads. And since each mile of road uses about 650 tons of asphalt, and each ton of asphalt typically takes about 2 gallons of fossil fuel to produce—that’s a big savings.