Today, it is common to see autonomous vehicles in operation on the streets of major cities in California, Arizona, Texas, and Florida. Waymo alone provides about 400,000 paid rides per week across Phoenix, San Francisco, Los Angeles, Atlanta, and Miami. Additionally, though less evident on the street, the adoption of full self-driving (FSD) mode by Tesla drivers is skyrocketing. By the end of 2025, the number of Tesla drivers worldwide with paid FSD subscriptions reached 1.1M, representing a 38% increase year over year. Of the total, the US accounted for about 600K or 55% of the total number of FSD subscriptions with most of those drivers reporting frequent use of the feature. And while the adoption of autonomy for commercial vehicles is still nascent, the number and scale of pilots is growing rapidly with one operator alone reporting 10,000 plus freight hauls and three million autonomous miles.

As autonomous driving system technology continues to mature, it is inevitable that transit agencies will adopt autonomous buses to support their transit mission, especially given the meaningful benefits of autonomy – e.g., safer roads, smarter traffic flow management, 24X7 on-demand capability, superior unit economics, and capital efficiency. Therefore, transit agencies must start now to acquire critical capabilities to not only manage individual autonomous buses, but to manage the complexity of a hybrid network, meaning a mix of human driven and autonomous vehicles, for the foreseeable future. More specifically, transit agencies need to prepare to adapt and enhance critical aspects of their business processes, such as evolving their service monitoring and management functions to enable autonomous vehicles to operate in a network with human driven buses to achieve shared (and interdependent) standards for safety, reliability, and accountability across the integrated transit network.

The overall adoption curve, which is uncertain, for autonomous transit vehicles will impact the mix of autonomous and human-driven vehicles across the US transit fleet, which now totals about 155,000 vehicles (excluding rail vehicles) according to the American Public Transportation Association and the US Department of Transportation’s Federal Transit Administration national transit database. Despite the uncertainty of the overall rate of adoption, we can assume the adoption curve for autonomous transit vehicles will mirror the experience in other sectors, with the adoption of smaller form factors occurring ahead of larger industrial grade vehicles. The approximate 155,000 US transit fleet vehicles are roughly evenly split between large buses used for fixed routes and smaller buses (or even vans) used for on-demand or microtransit purposes with large buses accounting for about 75,000 to 85,000 transit vehicles and smaller buses (or vans) accounting for about 65,000 to 75,000 transit vehicles. Therefore, should autonomous vehicles penetrate even 5-10% of the on-demand and microtransit fleet in the next 3-5 years, the US will have between 3,250 and 7,500 autonomous transit fleet vehicles on the road capable of enabling full-coverage connectivity across entire communities, and connecting tens of thousands of people to jobs, healthcare, education, and essential services. And, the initial phase of deployment of autonomous on-demand and microtransit services will enable agencies to collect real-world data for future fixed route configuration, build public familiarity with autonomous transit, and provide a phased, low-risk approach for broader deployments of autonomy.

At the midpoint of this range, the approximate 600 urban transit agencies providing on-demand and technology-enabled microtransit service in the US will on average have almost 10 autonomous vehicles in their fleet within 3-5 years. While this may seem like a relatively modest number, to ensure the safe and effective operation of these autonomous vehicles as well as the seamless integration of these autonomous vehicles into the fleet of existing human driven vehicles, transit agencies need to start now to define their autonomy strategy, as well as begin to build internal capabilities to operate these autonomous vehicles holistically within their overall transit network. Indeed, the site configuration, service configuration, service orchestration, service management, depot management, and data and performance management functions are distinctly different for autonomous transit vehicles than for human-driven fleets, yet these functions must also be integrated into the processes of the overall transit network to realize the full potential of autonomy.

Autonomous transit fleets must be viewed as part of the US transportation critical infrastructure ecosystem, and these fleets rely on software, cloud platforms, wireless connectivity, and vehicle-to-everything (V2X) communication creating a large attack surface. Therefore, transit agencies must develop domestic capabilities to manage cyber and physical risks that can affect both the security and operational resilience of autonomous transit fleets. This is especially important given the critical national infrastructure interdependencies in related infrastructure sectors, such as energy, telecommunications, emergency services, and supply chains.

Again, given the profound social and economic benefits of autonomy, its adoption will continue to grow and within the relatively near-future transit agencies across the US will be deploying autonomous fleet vehicles, especially for on-demand and microtransit service, which is the most natural, scalable, and community-aligned pathway for near-term autonomous transit due to manageable, lower-speed, well-defined zones with predictable traffic patterns and simpler operational design domains. In the face of autonomy’s inevitability, it is essential that transit agencies start now to develop the operational capabilities that are critical to the successful deployment of autonomous transit fleets. Fortunately, there are already successful deployments of autonomous microtransit services in the US, such as the Jacksonville Transportation Authority Neighborhood Autonomous Vehicle Innovation (NAVI) system (which is the nation’s first fully autonomous, fare-paying public transit system) and the Atlanta Beltline Autonomous Transit Pilot that will connect the West End MARTA, Lee & White District, and Atlanta University Center Hub to the Atlanta Beltline. These and other autonomous transit fleet initiatives provide valuable best practices for other transit agencies, as they adopt autonomy within their operation.