For someone without reliable access to a car, a bus that comes once an hour is not merely inconvenient; it can limit their ability to live a full and independent life. Transit systems should prioritize dependable access for people who cannot reliably drive themselves or afford private alternatives, including low-income households without cars, people with disabilities, older adults, teenagers, and workers sharing a limited number of vehicles.
A “transit-dependent rider” is someone who does not have reliable access to an automobile. They may occasionally borrow a vehicle, travel with relatives, or pay for a taxi or ride-hail service. According to the U.S. Census Bureau’s 2024 American Community Survey, approximately 10.8 million U.S. households have no vehicle available. Since households without vehicles are disproportionately lower-income, many are poorly positioned to absorb a $20 or $30 ride-hail fare. Serving these transit-dependent, or “captive,” riders does not require operating a fixed-route bus on every street. Postwar metropolitan areas can instead provide a layered transit system made up of several types of service.
A transit agency’s obligation should be to provide practical access to the destinations riders need to access. That means enabling riders to reach jobs, healthcare, education, groceries, and other essential destinations within a reasonable amount of time and during the hours when those destinations are available.
This creates a tradeoff between coverage and ridership. Fixed-route buses perform best where many riders travel along common corridors. One driver and one vehicle can transport 30, 40, or more passengers. When enough passengers share the service, its available seat-miles are put to productive use, and the cost per passenger can fall. In lower-demand areas, however, the same bus may carry only two or three passengers while still incurring substantial costs for its driver, fuel, maintenance, and administration. Much of its capacity goes unused, so the efficiencies of a large vehicle are not realized. The objective is therefore to match vehicle size and service type to actual travel demand, rather than supply the same bus service everywhere.
The service that makes the most sense depends on geography and demand. In higher-density areas, fixed-route buses generally work best because many riders can travel along the same corridors and occupy larger vehicles, allowing agencies to provide frequent service at relatively low cost per passenger. In lower-density areas, where trips are more dispersed, demand-response service or microtransit can provide local mobility and first-mile/last-mile connections to higher-capacity routes. Limited ride-hail subsidies can fill especially low-volume or late-night gaps without requiring fixed-route buses to run where few passengers use them.
In 2015, Houston’s METRO redesigned its fixed-route bus network to better reflect shifts in population and job centers, particularly in denser, higher-demand parts of the city. As part of that effort, METRO increased the number of routes offering service every 15 minutes or better. The redesign illustrates where fixed-route service is most effective, namely in corridors where enough riders can be concentrated to support frequent service and keep vehicles well used throughout the day.
Utah offers a corresponding example for areas with lower and more dispersed demand. In late 2019, the Utah Transit Authority (UTA) launched an on-demand microtransit pilot in southern Salt Lake County that allowed passengers to request shared rides within a service zone and connect to TRAX and FrontRunner instead of relying exclusively on a fixed bus route. UTA later identified many of its strongest microtransit opportunities in lower-density suburban, rural, and industrial areas outside Salt Lake City. In Utah and in other areas where trips are too dispersed to support frequent fixed-route service, agencies can use flexible service to provide local access while still connecting riders to the broader transit network.
The broader lesson is that agencies can use frequent fixed routes where demand is concentrated and flexible service where trips are dispersed, while periodically reassessing whether changing travel patterns justify a different service type. With limited resources and unmet needs, transit agencies need to become more creative in their service. Local buses are the backbone of most transit networks. However, agencies must also provide quality, cost-effective transit for lower-density areas and targeted populations.