Some bus riders say that they look forward to riding the train instead.
"Of course I would make the switch. That's the best thing that came to East L.A. in a long time. It's a quick way to get down there real quick without the sun and everything else. It's great," said Jonathan Barajas, an MTA bus rider.
Along with the rail line, almost $500 million has been invested along the line's route including three new schools and a new LAPD station.
"So what this rail line will do, it's kind of like a cherry on top of the number of new improvements in this area. It's going to help a lot to make people proud of where they come from and where they grew up," said Jose Huizar of L.A. City Council.
Mariachi Plaza is one of the eight stops along the eastside extension. Crews are working on last minute details, and local businesses and musicians are looking forward to the grand opening coming up.
"Mostly, it's going to attract more people and more tourists. That's the main thing, we need more people to come and see how our traditions prosper," said mariachi musician Cesar Gutierrez.
However, L.A. County Supervisor Gloria Malena has raised the issues of safely along the route where schools are located. Potential riders raise those concerns as well.
"It passes by three churches. There's always a lot of traffic, especially on the weekends, there's a lot of people walking around and little kids running around not always looking at the lights. I just feel it's a ticking time bomb," said Luis Plascencia, an MTA bus rider.
An MTA official said that safety near some of the "tricky spots" are of concern. He added that MTA employees will be out this weekend doing their best to educate drivers and pedestrians on how to safely maneuver around the trains.
Officials say that fencing will go up around some of those "tricky spots" to prevent pedestrians from jay walking across the tracks.
MTA will be offering commuters free rides all day Sunday.
Opening day festivities will also include a mariachi festival, a farmers market and an early visit from Santa Claus.