DENVER -- -- Nearly seven years after the start of its construction, T-REX is now extinct, and Light Rail is buzzing up and down the Interstate 25 corridor from south of Park Meadows Mall all the way to downtown Denver.

Saturday was the second full day of service, free to all customers who hopped aboard.

There were some issues Saturday morning with parking. Some riders at 9 Mile Station reported there wasn't enough parking.

"It was madness," said Maggie Ruby.

But for the most part, riders seemed thrilled with the experience. Many felt as if they were part of history in the making.

"Oh, it's great. I think we're going to use it a lot," said Crystal Kraft of Lone Tree.

"Well, we had to experience the light rail because this is history and we are so thrilled with Denver, Colorado," said Suzanne Hagen who was born and raised in Denver.

Some said it brings the east out west, as Denver steps into a new age of mass transit.

For Duffeyrolls off Louisiana and Pearl, light rail's expansion is right on track.

"We've been open for a little less than two months now, and today has been the busiest day we've had. That's all credit to light rail," said Duffeyrolls assistant manager Sarah Meister.

Some riders did criticize RTD because garages were already packed on the first weekend. That could be a result of the free rides. However, some business and homeowners have concerns about overflow. New signs at one business warn you that illegally parked vehicles will be towed.

But for 90-year-old Millie Kolquist, it's something long overdue. Kolquist said everything old is new again.

"I've been in Denver since 1916. I was born here. I remember the street car. We had tracks all over," she said.

RTD said it carried a record 75,000 passengers Saturday.

The true test for these new lines could come in the next couple of days. On Sunday, the Broncos play host to the San Diego Chargers in a night game at Invesco. And then on Monday morning back to work crowds should also be a good test.