Propane Autogas (LPG)
Propane used as a vehicle fuel. Common in school transportation, and cheaper to set up than natural gas because it stores as a liquid at low pressure.
Propane autogas is stored as a liquid under modest pressure, which makes its fueling infrastructure much simpler and cheaper than compressed natural gas: a tank and a dispenser rather than a compression plant.
School transportation is where it appears most, where buses return to one lot nightly and the lower infrastructure cost suits a district budget. Cold-weather starting and reduced idling emissions are often cited reasons in that setting.
