mr. fred smith this morning from fedex on the use of gas, natural gas in their fleet. and in my district, with the basin, fayetteville shale and gas plays that are happening throughout the country, there seems to be growing demand for compressed natural gas as a mobility fuel. however, chicken and egg, we don't have the infrastructure involved helping me get to where that readily available resource can be put to good use. >> first, i agree completely with fred smith about his assessment of liquefied natural gas in heavy trucking. couple hundred filling stations on major interstates, that's a significant part of energy use. that's 20%. you can offset a lot of that. we looked at the numbers. it looks very promising. payback periods, something on the order of three, four years for an investment in more expensive truck. the filling station the private sector is getting behind and investing hundreds of millions of dollars. so the heavy trucking, very few filling stations, we think it's a great way to diversify our energy supply. when you go to delivery vans and personal veh