Hydrogen fuel used in fuel cell vehicles provides the potential for significant benefits from the perspective of greenhouse gas emissions, urban/criteria air pollutant emissions and energy security. However, the precise environmental impacts will depend upon the specific details of the configuration and operation of the hydrogen infrastructure. In addition, the costs, emissions and energy requirements for hydrogen infrastructure depend upon a number of important factors including the choice of primary energy feedstock, type of production facility, and the methods for hydrogen delivery to refueling stations. The system design, cost and emissions also depend upon the specific geographic and demographic characteristics of each region or city, including the total city hydrogen demand, the physical size and density of the city, the cost of fuels and energy feedstocks and the emissions and energy efficiency of local electricity generation. In this paper, we examine how each of these considerations affects the cost of providing hydrogen at refueling stations at various levels of market penetration of fuel cell vehicles. To carry out this study, we have developed a user-friendly, EXCEL-based analysis tool to estimate costs and environmental impacts of a variety of hydrogen infrastructure pathways, including production, delivery and refueling. The model is applied to estimate hydrogen infrastructure cost, delivered hydrogen cost and CO2 emissions for the 73 largest urban areas in the United States, which encompass a range of different sizes and geographic and economic factors. The model (called the Steady State City Hydrogen Infrastructure System Model or SSCHISM) uses US census data (US_Census_Bureau, 2000) to estimate hydrogen demand and an idealized city model to determine the delivery system layout for trucks and pipeline delivery (Yang 2006). The model calculates the infrastructure capital cost and levelized cost of hydrogen for each city, as a function of the choice of hydrogen pathway, market penetration and average station size. The model determines the lowest-cost pathway for each city and allows comparisons of the cost, emissions and energy efficiency for a given hydrogen pathway for all cities. The model also allows users to select economic and technical assumptions from several sources, including the National Academies' Hydrogen Economy report (NRC, 2004), the DOE's H2A models (H2A, 2005) or user-defined assumptions. Model results show that early market hydrogen will be supplied by onsite natural gas SMR at the refueling station, while at 100% market penetration, hydrogen from central production (mostly coal) will dominate. Once central production is favored, the distribution mode depends upon city density and size, with smaller, lower density cities favoring liquid truck delivery and larger, higher density cities favoring pipelines. Hydrogen costs vary significantly between different parts of the country based on the size of production facilities, feedstock costs, size of distribution systems and electricity costs. Emissions and energy inputs can also vary significantly among cities depending upon the composition of the local electrical grid, especially for electricity-intensive liquid delivery pathways.