In Brief:
- San Jose bus speeds improved by 20 percent after the city deployed a traffic signal prioritization system developed by the tech firm LYT.
- The system predicts the timing of when vehicles will approach an intersection and manages signals to keep them moving.
- The system is in use in other cities as well.
Buses are moving faster through the streets of San Jose after the city adopted a traffic signal prioritization tool developed by an area tech company.
The product, called LYT.speed, optimizes traffic flow for the Santa Clara Valley Transit Authority by monitoring the movement of buses and giving them green lights before they approach an intersection. A pilot program on two bus routes in 2023 cut red-light waiting times in half, according to a city press release. The city has since expanded the program to all of its bus routes, resulting in 20 percent faster travel times. The outcome is evidence that “local government can deliver results where it matters most,” San Jose Mayor Matt Mahan said in a State of the City address earlier this year.
Traffic signal prioritization systems have been around for decades. Basic systems allow buses or emergency vehicles to switch traffic lights when they approach, using loud sirens or flashing lights as the trigger. The San Jose system, developed by the firm LYT, based in nearby Santa Clara, is more sophisticated. The program tracks the movement of buses using transponders that are already installed on the vehicles. It predicts their approach to traffic lights and automatically operates the signals to help them keep moving. Timothy Menard, LYT’s CEO, compares it to air traffic control.
“Our system is set up like a huge regional operator,” Menard says. “We’re able to see all the transit vehicles, where they’re going, and we also know the bus route — where the bus stops are. We have an understanding of the full picture.”
The system uses artificial intelligence tools to analyze real-time data and historical data and predict buses’ location two minutes in advance. That allows it to adjust signals and keep all traffic moving more smoothly, where traditional signal systems would trigger a green light for vehicles only when they were already close to the intersection. It minimizes disruptions for other drivers and pedestrians.
“People don’t even realize that the streets of San Jose are now completely calibrated to the needs of transit,” Menard says.
LYT developed the system for the city and the transit authority, initially pitching them a product that would predict when traffic lights would change. The transit authority said it would be more useful to actually operate the traffic lights instead. The tech doesn’t require the installation of any additional hardware.
Stephen Caines, San Jose’s chief innovation officer and budget director, credits a “spirit of open collaboration” among public and private entities in Silicon Valley for developing tools that help the government work better. The back-and-forth between government agencies and tech providers has helped refine tools like LYT’s traffic signal prioritization system. In recent months, the city has experimented with a different way of procuring tools to solve city problems. While cities typically issue requests for information (RFIs) from vendors as a first step in acquiring new products or services, San Jose has begun holding “pre-conferences” with past vendors to talk informally about what the government needs and what the vendors might be able to provide.
As the chief innovation officer, Caines says he often acts as a “filter” for tech leaders that want to offer products to the city. “If I think there’s value and we can afford it, I’ll pass you on to the right person. If not, I’ll thank you for your time,” Caines says.
San Jose has used AI tools to address other challenges as well. One, called CivCheck, is meant to speed up the development process for accessory dwelling units by making sure homeowners’ permit applications are complete before they’re submitted, cutting down on processing times. Another, called BurnBot, helps manage brush to prevent and mitigate wildfires. With LYT, the city is hoping to not just speed up the buses but improve traffic generally and make public transit more appealing.
“Is it possible to enhance the bus-riding experience and encourage other folks who may not otherwise have considered [riding the bus]?” Caines says.
San Jose was LYT’s first client. But Menard says the company has now deployed its traffic signal prioritization tool in most major metro areas on the West Coast, along with Nashville, Boston and other cities. Portland, Ore., reduced wait times for some of its buses by 80 percent after implementing the LYT tool. Public agencies are using AI tools to solve other transportation-related problems too, like automating enforcement of parking violations in bus lanes. Menard says after emergency vehicles and buses, the next step is to work with commercial and delivery fleets for signal prioritization, which would have further benefits for the flow of traffic.
“It’s like building a layer cake,” he says. “Once the foundation is set correctly, you can bring in the next one and the next one.”
