New estimates out from Metro, first seen on The Source, show that February was the Expo Line’s best month to date. The numbers indicate that weekday ridership was up to 55,388, an increase over the previous month’s weekday estimate of 53,473.

The busiest day of the weekend was Sunday, when rider estimates hit 38,625, but that was a marked drop from the previous month, when Sunday ridership was 44,252.

The Source’s Steve Hymon tells Curbed that the Expo Line’s new high numbers are probably due to trains arriving more frequently during rush hour; starting in October, they began running every six minutes.

He also said, “Expo continues to serve a corridor where there was a lot of pent up demand for rail transit owing to Westside traffic.” Metro has said that it is attracting riders who normally would have commuted by car to work, though many of those riders are liking taking the train infrequently.

Metro’s data for ridership on the Expo and on all its lines uses information that’s been collected over a six month period. That’s why a change made in October affects the newest numbers, because the period that produced the February estimates started in September.

Hymon says while it might be “more ideal” to have numbers for each month alone, when the numbers for previous months are examined next to the February estimates, “you can see the numbers going up and down over the months and years and I do think the estimates capture what is happening on the system.”

New lines that opened this year—the Expo Line extension to Santa Monica and the Gold Line extension to Azusa—have helped Metro’s rail lines bring in new travelers, but overall, the agency has lost riders, especially on bus lines.