Last week, the King County Executive’s office announced that the Seattle area is growing its transit ridership faster than anywhere else in the country, adding 4.7 million trips in 2017 for a total ridership of 191.7 million, higher than the region has ever seen.

The Executive attributes this explosive growth to increased options. “People wanted more bus and light rail options, and we delivered. More service means more riders,” said Executive Dow Constantine in a statement.

It’s certainly a big part of the story—the University District station of Link light rail opened less than two years ago, meaning more people have connections to higher-speed transit. The region’s bus rapid transit options have expanded, too.

“The connections that Metro has been able to create with light rail have been really powerful in creating that option for people,” King County Metro service planning supervisor Katie Chalmers told Curbed Seattle. She said that “it can take two or three years after a major service change” for people to adjust their habits, putting the Link extension solidly in that window.

“As Link expands and as Metro is able to make those connections with light rail, that’s a big reason why ridership growth in Seattle is bigger than some areas around the country,” said Chalmers.

But the increase in ridership is also a sign of a growing city, one of the fastest-growing in the nation, full of new people that have to get around. If it were a matter of ridership growing along with expanded options, overcrowding would be less of an issue. It’s something that Metro acknowledged in its annual system evaluation this past fall, identifying problem routes like Rapidride C, D, and E.

“There’s definitely times that are growing faster than we can meet just on service change to service change,” said Chalmers. “It’s actually a really exciting time to be in service planning because Metro has had a really positive budget… here’s a major crowding problem, let’s do something about it.”

While Metro can’t always predict the next route that will experience overcrowding, especially since the data it uses to make adjustments to routes has a delay attached—data collected from March through June was analyzed for the fall system ealuation. But they can direct more resources to known problem routes—and enhance service to more limited routes to try to get ahead of it.

Service changes coming this March will address some specific overcrowding issues, as previous adjustments have, and also add service to routes that seem a little thin.

“We’ve added more than 50 trips last year just to get at those routes that are most crowded,” explained Chalmers. “In March we’re going to add 15 to 16 more trips [just during peak hours],and have room for 50 to 60 more people to get on the E Line or the 40 —on these routes that we have a lot of problems occuring.”

For example, route 70 has experienced consistent crowding during the summer bringing UW students to employment in South Lake Union, so Metro is adding more seasonal trips. Meanwhile, as demand for travel to the University District only increases, Metro will be expanding service hours to the 31, which doesn’t currently have an overcrowding problem but still has consistent ridership.

“One change I thought was really exciting is between Renton and Kent there’s a route that’s operated every 30 minutes for many many years and it’s a corridor that we felt had a lot of latent demand,” said Chalmers. “It wasn’t having crowding problems, but you go out to the route and it had really solid ridership... things like that are really game changers for people riding the bus throughout the county… and going from 30-minute to 15-minute service really changes the way you can use transit to travel.”

King County Metro spokesperson Jeff Switzer said service adjustments have three top priorities, in order: Crowding, reliability, then service growth. Changes like this—these “chunky adds,” as Chalmers called them—fall into the core-level service adjustments that make up that third category.

That middle priority, reliability, also affects crowding; it means “not only adding more trips to provide more capacity but also making sure our schedules are as accurate as possible so that people know when to expect the bus,” said Chalmers.

“Metro can only control what Metro can control,” added Switzer, noting an incident earlier this week here a driver hit a pedestrian, closing all directions of Third Avenue—and nodding to an incident a few years back where a fish truck tipped over on the Viaduct.

“Twitter’s a good signal for us and we watch customer complaints” when the traffic grid is locked up, said Switzer, “because they come in real time.”

Working with “partner cities” to implement things like bus lanes, said Chalmers, is “actually a big part of how we deal with crowding as well, because we can spend less time just sitting there.”

Although implementation isn’t perfect, said Chalmers, people clamoring to get on the bus isn’t the worst thing.

“It’s a good problem to have that we have high demand and it’s growing fast,” said Chalmers. “We’re doing our best to keep up.”