The emergence of natural gas as an abundant, inexpensive fuel in the United States has highlighted the possibility that natural gas could play a significant role in the transition to low carbon fuels. Natural gas is often cited as a “bridge” to low carbon fuels in the transportation sector. Major corporations are already investing billions of dollars to build infrastructure to feed natural gas into the U.S. trucking industry and expand the use of natural gas in fleets. In the state of California, natural gas fueling infrastructure is expanding, especially in and around the ports of Los Angeles and Long Beach. The use of natural gas fueled medium and heavy-duty fleets is currently on an upswing. The emergence of new interest in investment in natural gas fueling infrastructure in California raises the question regarding whether natural gas infrastructure could become stranded by the ultimate shift to lower carbon fuels or whether the natural gas infrastructure system offers synergies that could potentially facilitate speedier adoption of lower carbon fuels. Industry has advocated that overlap of key natural gas infrastructure will lower transition costs and provide consumers with an optimal mix of fuels as the state’s commercial vehicle stock is replaced with alternative vehicles over time. Development of alternative fuels that have low greenhouse gas emissions and low criteria pollutant emissions, such as renewable natural gas and hydrogen, are considered a major avenue for the state of California to meet climate change and air quality goals. We examine the precise natural gas infrastructure that is economically and technologically synergistic for both natural gas and renewable natural gas in the near-term, and alternative fuels like renewable natural gas (RNG) and hydrogen in the long term. In particular, we examine optimum paths for developing infrastructure in the near-term that will accommodate alternative fuels once they become available at the commercial scale. The original design of the Low Carbon Fuel Standard (LCFS) provides time for the development of advanced, near-zero technologies. We consider the credits from the LCFS in our analysis. We find that infrastructure requirements for natural gas and renewable natural gas (RNG) have many synergies. Emerging RNG supplies can utilize much of the same infrastructure as fossil natural gas networks, sharing the same vehicles, station equipment and midstream pipelines for transmission. The time frame for availability and opportunity are also contiguous, allowing for RNG and fossil natural gas networks to be developed simultaneously, each facilitating the other. Fossil natural gas network investors can benefit from receiving carbon credits by blending RNG into their fossil based natural gas fuel while RNG investors can save costs by piggy backing on existing fossil natural gas infrastructure. There substantial sources of RNG in California that are commercially competitive with existing fossil fuel-based transportation fuels because carbon externalities are taken into consideration in the California market through existing programs such as the Low Carbon Fuel Standard (LCFS) and the U.S. Renewable Fuel Standards (RFS). Those resources will be enabled by the build-out of natural gas infrastructure and adoption of natural gas fueled vehicles for commercial transportation. Liquefied natural gas (LNG) fueling stations for heavy trucks now exist in over a dozen locations around the state of California and continue to expand. But widespread adoption of RNG will require new facilities for the clean-up and upgrading of biogas from anaerobic digestion and collection of landfill gas. Thus, price support for RNG through LCFS credits, RFS credits and higher tipping fees for municipal solid waste can be influential in propelling replacement of fossil natural gas with lower carbon gas from bio sources. The minimal price support required by each pathway in order to compete with fossil natural gas is $11.50, $3.75, $5.90, and $26.00 per mmBTU for MSW, Landfill, WWTP, and Dairy, respectively. In per gasoline-gallon-equivalent (gge) terms, the minimal price support required by each pathway is $1.38, $0.45, $0.71, and $3.15 per gge for MSW, Landfill, WWTP, and Dairy, respectively. Hydrogen fuel cell passenger cars are now being introduced in California, with tens of thousands of vehicles expected by the early 2020s, served by 100 or more public stations, located primarily in urban areas. However, the best synergies with natural gas vehicles and infrastructure, in terms of both equipment and location, may involve transitioning from compressed natural gas to hydrogen in freight applications. Initial infrastructure roll outs for medium and heavy duty trucking can register early success through pilot programs for short-haul applications such as last mile deliveries and drayage trucks, where back to base stations “behind the fence” facilities can promote use by fleets. Industry estimates are that it will take roughly 7 to 15 years before new truck platforms can be designed and built, leveraging equipment development for successful bus and truck fleets. Private stations for hydrogen for medium and heavy duty vehicles with short haul applications would supplement or replace vehicles running on compressed natural gas (CNG) derived from fossil natural gas or renewable natural gas. “Behind the fence” facilities overlap between CNG and hydrogen will build off the same pipeline connections if hydrogen is reformed from fossil or renewable natural gas. Separate storage facilities and refueling equipment will be needed for a transition from natural gas or RNG to hydrogen fuel. Co-location of fueling infrastructure for natural gas, RNG and hydrogen may lower overall costs but the need for costlier equipment to handle hydrogen, which can be more corrosive to pipeline and storage materials than natural gas means higher credits and incentives compared to renewable natural gas would be important to drive a widespread adoption of hydrogen as a fuel for medium and heavy duty commercial vehicles. While California has already begun the process of adding public hydrogen stations for primarily serving passenger vehicles in urban locations, the timing for the likely build-out for hydrogen stations serving new, hydrogen-ready trucks and buses will likely be a decade or more later than the current expansion of the fossil natural gas and RNG networks, limiting some of the potential for synergies for overlapping infrastructure for commercial fleets. Natural gas fueling infrastructure built today will need to be refurbished or replaced within 15 years, while hydrogen networks are likely to only reach wide scale adoption in that timeframe. However, advanced planning for eventual addition of hydrogen fueling infrastructure at new compressed natural gas and liquefied natural gas fueling locations can facilitate the adoption of hydrogen fuel at a later date and smooth the transition to near zero carbon technologies. Our analysis shows that certain port and urban locations will favor renewable natural gas resources initially but may be able to link to hydrogen supply chains in the longer term.