The anticipated expansion of weekend and late-night SunRail service may not happen until 2020 or 2021.

That's because for now, the catalyst for the expansion is Phase 3 of the SunRail project, which would connect the main line with Orlando International Airport. That project isn't expected until 2020 at the earliest, according to Orlando and SunRail officials.

Right now, SunRail, which began in 2014, only runs Monday through Friday, except for rare, special-event service. But because of the 24/7 nature of the airport, weekend and late-night service would be added as a necessity.

"It is not only a possibility, it will have to happen," Orlando Mayor Buddy Dyer said after delivering Tuesday's State of the City address.

SunRail officials echoed Dyer when it comes to expanding services to late nights and weekends.

"We’re looking to get to the (Orlando International) airport, and I think one of the things that’s really important about the airport is that you can’t just have a Monday-through-Friday, commuter rail train because the airport is 24/7," SunRail Project Manager Tawny Olore said.

Olore said funding partners agreeing to spend more money for night and weekend service is the penultimate hurdle.

SunRail passengers said they were pleased with the current service but said expanded service would be more convenient.

“It’s a smooth ride. It’s real comfortable. The conductors are really nice. It’s good," said SunRail passenger Sam Clay, who lives in downtown Orlando but works in Sanford. But “If it worked on weekends and it worked late at night for people that work out in Sanford and Altamonte Springs, it would be more convenient for them," Clay said.

“If the SunRail worked until 10 or 11 o’clock (at night) during the week, it would be more beneficial to a commuter that actually gets of work at a later hour," Clay said.

The Riggin family, visiting Central Florida this week from Atlanta, wanted to ride SunRail to explore downtown Orlando on Tuesday night but thought otherwise.

“It stops running kind of early for us being on vacation," Denise Riggin said. "We ended up just driving and just paying to park.”

Riggin and her husband, Nicholas, gave SunRail another try, traveling from Winter Park to Church Street Station on Wednesday morning. It was a successful alternative commute for the Riggins.

"Last night when we came downtown, parking was really difficult to find a place to park. It was kind of confusing being an outsider, not being familiar with the city," Nicholas Riggin said.

How is SunRail ridership fairing?

In March 2016, 88,296 people rode SunRail.

That’s an average of 3,839 per day.

Officials said that’s slightly down compared to last year.

They think low gas prices and severe weather are partially to blame for the decrease.

SunRail is hoping a new marketing plan allowing riders to “try out” SunRail for free and will lead to a long-term boost in ridership.