Patronage has fallen in many of the other top 50 transit markets. This report discusses the implications of recent trends in transit ridership for future federal policy. If the New York region is excluded from the data, national transit ridership decreased by 7% over the past 10 years. These new rail lines, however, have not necessarily boosted transit ridership overall. Factors Affecting Public Transportation Ridership

There is no comprehensive explanation for the overall decline in ridership outside of New York. National trends in public transportation ridership are not necessarily reflected at the local level; thus, different areas may have different reasons for growth or decline. Probably the two most relevant factors in the current context are the attractiveness of other transportation options and transit service supply issues. Among the factors that account for transit ridership changes within the United States is the price of gasoline. Ridership fluctuations over the past decade seem to track changes in the average annual price of gasoline ( Figure 5 ). Public Transportation Service Supply

Among the factors that affect public transportation ridership, service supply variables are typically some of the most important. It appears that public transportation fares per unlinked trip have generally risen faster than inflation in recent years. The Future of Public Transportation Ridership

In the short to medium term, roughly 10 to 20 years, transit demand is likely to be determined by population growth and the public commitment to supplying transit. These include the extent, duration, and intensity of highway congestion; the price of parking; and the implementation of fuel taxes, tolls, and mileage-based user fees. Based on the introduction of past vehicle technology, it is likely that even if fully autonomous vehicles are available in a few years, it will take decades for them to become ubiquitous. Fleets of driverless taxis that can be hailed with a smartphone could potentially offer service much more cheaply than taxis and ridesourcing do today, as labor, which makes up about half of the cost of such a trip, would no longer be a significant factor. Widespread deployment of autonomous vehicles and driverless taxis, therefore, could lead to a greater number of vehicle trips and a decline in traditional transit ridership. Second, through the Capital Investment Grant (CIG) program (also known as the New Starts program), the federal government plays a significant role in the building of new transit rail and bus rapid transit systems and the extension and expansion of existing systems. Federal Public Transportation Funding

			Incentive Funding

National transit ridership is somewhat dependent on the level of federal funding. A key policy issue is whether future federal funding should focus on buses, which last about 10 years and can be redeployed as demand changes, rather than on rail systems that last 30 years or more and are inflexible but are far more efficient at transporting large numbers of passengers in dense corridors. Another option would be to redirect CIG funding from building rail and perhaps even bus rapid transit in relatively small and dispersed urban areas to the large and dense cities where rail transit currently carries very large numbers of riders, such as New York, Chicago, and Washington, DC.
Despite significant investments in public transportation at the federal, state, and local levels, transit ridership has fallen in many of the top 50 transit markets. If strong gains in the New York area are excluded, ridership nationally declined by 7% over the past decade. This report examines the implications for federal transit policy of the current weakness and possible future changes in transit ridership.
Although there has been a lot of research into the factors that explain transit ridership, there seems to be no comprehensive explanation for the recent decline. One complication is that national trends in public transportation ridership are not necessarily reflected at the local level; thus, different areas may have different reasons for growth or decline. But at the national level, the two factors that most affect public transportation ridership are competitive factors and the supply of transit service. Several competitive factors, notably the drop in the price of gasoline over the past few years and the growing popularity of bikeshare and ridesourcing services, appear to have adversely affected transit ridership. The amount of transit service supplied has generally grown over time, but average fares have risen faster than inflation, possibly deterring riders.
The future of public transportation ridership in the short to medium term is likely to depend on population growth; the public funding commitment to supplying transit; and factors that make driving more or less attractive, such as the price of parking, the extent of highway congestion, and the implementation of fuel taxes, tolls, and mileage-based user fees. Over the long term, ridership is also likely to depend on the introduction of autonomous vehicle technology, although its timing is uncertain. Fleets of driverless taxis that can be hailed with a smartphone, a plausible scenario, promise to be much cheaper than taxis and ridesourcing today. Widespread deployment of driverless taxis could reduce transit ridership, unless restrictions or fees make them an expensive alternative in some areas.
Two major federal transit policies related to these issues are the general funding of public transportation, distributed mainly by formula, and the discretionary funding of new large capital projects such as rail and bus rapid transit systems through the Capital Investment Grant (CIG) Program, also known as New Starts. One option to boost ridership without raising funding would be to tie federal formula funds to ridership or fare revenue. If the most consequential uncertainty for transit ridership is the introduction of autonomous vehicles, federal funding might focus on buses, which last about 10 years, and not new rail systems that last 30 years or more. Another option would be to redirect CIG funding from building new rail systems and lines to refurbishing rail transit in the large and dense cities where rail transit currently carries large numbers of riders. If fully autonomous ridesourcing vehicles become available, policymakers may face pressure to subsidize ridesourcing trips for disabled and elderly passengers alongside or in place of traditional transit and paratransit services.