The improvements in San Jose, ranked third by population with nearly 1 million residents, come not from major changes to the buses themselves, or the routes they travel — but from breezing through intersections, avoiding unnecessary slowdowns due to red lights.
The buses, operated by Valley Transportation Authority (VTA), the transit provider for San Jose and surrounding communities across Silicon Valley, benefit from transit signal priority technology, which allows some traffic signals along the route to transition to green when a bus approaches, eliminating what is often an unnecessary stop.
The project began as a pilot in 2023. Recent data shows bus speeds in San Jose have increased 20 percent, city officials said.
“It’s been really great to start with just a few routes, and then scale citywide,” Stephen Caines, the city’s chief innovation officer and budget director, said. He also serves as a senior adviser to Mayor Matt Mahan. “It’s really exciting to see these gains still exist as we’ve continued to expand the network and the routes.”
The technology, LYT.transit, provided via a partnership with LYT, offers cities the potential for a relatively quick win in improving transit, without the need for costly capital projects like dedicated bus rapid transit lanes or light rail lines.
The project “is modular, it’s scalable. We didn’t have to shut any roads down to introduce this technology,” Caines said. “This was the least friction way of enhancing our transit system.”
The transit signal technology is similar to other signaling pre-emption technologies used by emergency vehicles, which are designed to briefly reprogram traffic signals to provide a cascading stream of green lights, generally looking several miles or blocks down the route an emergency vehicle is traveling. The technology used for transit vehicle priority is designed to change the signal from red to green as the bus immediately approaches the intersection.
Both technologies have led to improved response times for emergency vehicles and improved service levels for transit vehicles.
“Any type of transit route benefits from the schedule reliability this technology provides to meet the goals of the intended transit route,” said Tim Menard, founder and CEO of LYT, an AI-enabled technology purveyor.
Following an initial deployment of signal priority technology in 2023, San Jose followed up with a wider deployment, aided by grant funding. Today, the technology is used at some point on all bus routes in the city, Caines said.
This level of scaling out the technology across a service area is central to seeing across-the-board gains in bus speeds, Menard said.
“Transit signal priority isn’t a spot treatment technology,” the CEO said. “It thrives on scale and, like compound interest, so do its benefits.”
Those service benefits align with some of the city’s broader goals around improving transportation, with transit viewed as one of those “large-scale impact initiatives” that can improve the everyday lives of San Jose residents, Caines said.
“We all know riding the bus can improve congestion, sustainability, and there may even be elements of social cohesion that could be advanced by sharing spaces and not having everybody in a single-occupancy vehicle,” he said, adding, the initiative to improve transit with transit signal priority “really checked all those boxes.”
In his State of the City address earlier this month, Mahan called out the project as one of the AI initiatives to emerge from City Hall, saying it serves to make “transit a more attractive alternative, reducing congestion, and improving our air quality.”
Another key AI-enabled project in San Jose is its “object detection pilot,” which uses AI and computer vision to identify objects in roadways and maintenance concerns like potholes. The city completed Phase II, with “very promising” results, Caines said.
Using the technology, city officials identified nearly 70 percent of issues before residents initiated a 311 request. The technology showed an accuracy rate of more than 75 percent across multiple object types including potholes, illegal dumping or oversized vehicles in unauthorized areas. The city will continue to study the project and plan its next phase, Caines said.
For his part, Mahan has appeared to endorse the civic mission of putting these technologies to work to improve the lives of residents and the work of City Hall.
“But we must do even more. In the coming years we must harness these new technologies to expand opportunity, not exacerbate inequality,” Mahan said in his Feb. 7 State of the City address. “We will ensure that every new data center creates a cleaner, more resilient grid, and uses less and less water. We will reimagine our curricula and our workforce development programs to train people for the jobs of the future.”
