Los Angeles transportation planners are already reprogramming traffic signals to speed up trains on Metro’s E (formerly Expo) Line, but more dramatic measures could ensure trains move smoothly through gridlocked streets.

Los Angeles City Councilmember Mike Bonin requested a report Wednesday from the city’s transportation department on the possibility of giving E Line trains traffic signal preemption when traveling through the city.

“I just want the trains to start moving a lot faster, like today,” said Bonin, who also sits on Metro’s Board of Directors.

Signal preemption would ensure the trains, which run at street level for much of the 15-mile trip from Downtown LA to Santa Monica, move seamlessly from stop to stop without being held up by red lights.

It would also likely require installation of new traffic gates and alarm bells to ensure intersections can be quickly cleared of oncoming traffic when trains are approaching. Drivers waiting at these crossings might also have to wait a bit longer since an oncoming train could end a green light period early.

Earlier this week, Mayor Eric Garcetti made speeding up transit a key piece of his plan to address climate change on a local level. An executive directive issued by the mayor directs city staffers to ensure public transportation speeds improve by 30 percent in time for the 2028 Olympics.

Since an extension of the E Line to Santa Monica opened in 2016, the train has been one of the most popular lines in Metro’s transit network. But the ride from Downtown LA to the coast isn’t always quick.

E Line trains travel through 22 street-level signals on their 15-mile journey, which can significantly delay trips for passengers. The trip is supposed to take 47 minutes, but often takes longer.

When trains get even a little bit behind schedule, they can get slowed down dramatically by red lights, especially through Downtown, where the Expo Line travels through the most non-gated intersections.

At a transportation committee meeting on Monday, Department of Transportation chief engineer Dan Mitchell explained that traffic signals in the city have always been set up to move trains through intersections as efficiently as possible. But trains at some busy stations take longer to board than traffic planners accounted for, which means they often miss the pattern of green lights meant to shepherd riders swiftly along the route.

Now the transportation department is working on a new system that Mitchell compares to “holding an elevator.” A preliminary test at the intersection of Exposition Boulevard and Normandie Avenue offered promising results. Prior to the change, nearly half the trains approaching the intersection got caught at a red light; after the new system went into effect, fewer than a quarter did.

Bonin, however, questioned Wednesday whether the city could go further in speeding up train service along the route, which carried 55,000 daily riders in January.

“Why can’t we just do signal preemption the whole way?” Bonin asked.

Signal preemption, which would force lights to change when trains are approaching, is already employed on parts of the E Line west of Crenshaw Boulevard. It’s notably lacking in the busy Downtown area, where trains can get caught in rush hour gridlock.

Mitchell cautioned that preempting traffic signals along the entire line could be disruptive to traffic flow on intersecting streets.

“Is that an approach for this corridor? We don’t know,” he said. “But we could anticipate that if we treat the train’s arrival as an unexpected surprise, it creates maybe more disruption for people who are walking across these large streets or waiting to make a turn to get across.”

Bonin requested that the department explore the idea further and report back to the committee at a later date.