The increase in domestic supplies of natural gas has raised new interest in expanding its use in the transportation sector. This book considers issues related to wider use of natural gas as a fuel in passenger cars and commercial vehicles. This book is designed to help fleets understand the cost factors associated with fueling infrastructure for compressed natural gas (CNG) vehicles. It provides estimated cost ranges for various sizes and types of CNG fueling stations and an overview of factors that contribute to the total cost of an installed station; and describes how the National Renewable Energy Laboratory (NREL) used the VICE model to establish guidance for fleets making decisions about using CNG.