|FHWA Policy Memorandums|
This figure shows an image of the square shaped ALTERNATIVE FUELS CORRIDOR sign with blue background and white legend and border. Below this sign are three smaller equally spaced square shaped General Service symbol signs representing three of the possible alternative fuels: Hydrogen (HYD), Liquefied Petroleum Gas (LPG), and Liquefied Natural Gas (LNG). These three General Service symbol signs have blue backgrounds with white legends and borders. The legend on these three signs is comprised of symbolic white colored figures of gas pumps with the following sets of three letters aligned vertically from top to bottom in the middle of the pump, one set of letters for each of these signs: HYD, LPG, and LNG.
United States Department of Transportation - Federal Highway Administration