Like most Washington-area residents, Banessa Moradi had a well-practiced routine for her morning commute. To avoid the rush at the Wiehle-Reston Metro station, she planned her arrival for around 10 a.m. Once there, she would pull into one of the many open spaces in the parking garage, then hop on a train.

But a few months ago, she began to notice a change: increasingly, she was arriving to find the garage was full. It happened so often that she eventually gave up. Now she just has her husband drop her off at the kiss-and-ride area.

“It’s just too crowded,” said Moradi, a senior business analyst from Sterling, who has been taking the Silver Line from Wiehle to her job in downtown Washington since the line opened in 2014. “It’s too much of a hassle.”

For years, commuters like Moradi, who hopped on the Silver Line at Wiehle for jobs in Tysons or the District, didn’t have to worry about parking. There always seemed to be room in the 2,300-space, seven-level garage. When it first opened, some joked that it would never fill. But no more.

The big mystery: Where are all the cars coming from?

The obvious explanation — that more people are parking at Wiehle to take Metro — doesn’t jibe with the numbers. Average weekday ridership from the station, which is the western terminus for Silver Line service, is well below what it was in 2015, when commuters say there was always space in the garage.

According to statistics provided by Metro, the number of average weekday passenger boardings in 2015 — the first full year that the Silver Line was in operation — was 8,588; garage utilization was just over 88 percent. So far this year, average weekday passenger boardings are 7,785 — about 800 fewer — but garage utilization in recent months has been nearly 95 percent, according to Metro, which operates the garage.

Could it be more bus riders using the garage as a park-and-ride? It’s unclear. Fairfax County officials added routes from the station, but they said a change this year in the technology used to calculate ridership means they can’t compare it with that of previous years. They note, however, that bus ridership overall has been on the decline since 2016.

It costs $4.95 a day to park in the garage. For an additional $65 a month, commuters can get reserved parking, which guarantees you a space if you arrive before 10 a.m. However, it does not appear the recent crowding has led to a rush to purchase the spaces. Of the 250 available reserved spots, 119 have been purchased — a number that has remained consistent since they became available, Metro officials said.

Metro officials say more businesses have opened in the area, which may account for some of tight conditions.

“Some of the increase in parking utilization may be attributable to people who are using the garage for non-Metro purposes,” Metro spokesman Ron Holzer said in an email.

But it’s not clear that is the case, either. An apartment complex atop the Metro station has its own garage. A branch of the popular Founding Farmers restaurant, which opened at the station in April, has its own customer parking. And commuters like Chad Clary doubt other businesses in the complex — including a nail salon and Starbucks — draw enough patrons during commuting hours to account for the increase.

Clary, an IT security consultant who drives to the station from Ashburn, said the garage is far more crowded than when he began using it in 2014. Arriving in the morning is easy: He gets there before 7 a.m. and parks in the same corner space on Level 7. But getting out at the end of the day — around 5 p.m. — has gotten more difficult. Clary said the garage is so full some days that commuters park in the traffic lanes. That means lanes normally wide enough to allow two cars to pass in either direction are narrowed so that only one can pass.

“It’s harrowing trying to pass through an area made for two cars that’s only wide enough for one,” he said. “It’s fine when all the traffic is going one way but less fine when you’ve got sports fans coming in mixing with commuters trying to get out.”

That was indeed the case on a recent weekday around 5 p.m. On level G-7, at least a half-dozen cars were parked in pass-through lanes rather than spaces, making it difficult for more than one car to get through. Other vehicles found space along various walls. None was ticketed for parking illegally.

When asked about the situation, Terri Seighman of Sterling just shook her head.

“There’s going to be an accident,” she said.

Robin Geiger, spokeswoman for the Fairfax County Department of Transportation, said so far this year, traffic enforcement officers have written just over 1,100 tickets at the garage — a significant increase from the previous year, when 474 parking tickets were issued.

In recent days, officials have begun putting warning fliers on the windshields of cars parked illegally, commuters said.

Of the tickets issued, Geiger said, roughly 31 percent were for violations that include parking in non-designated spaces. Other violations included displaying expired license plates or expired safety inspections. Tickets come with a $50 fine. Cars parked in spots designated for those with disabilities face a $500 fine.

Geiger said there is relief coming. The expected opening of the second phase of the Silver Line in 2020 will include five new garages — taking some of the pressure off Wiehle.