The latest additions to the Metro rail system are rapidly taking shape. On May 20, the Metro Expo Line will begin service to Santa Monica, and construction on the Crenshaw/LAX line has reached its halfway point.

Los Angeles Mayor Eric Garcetti and Metro officials this week took an early ride on the Expo Line with the mayor noting the route is a throwback to “what my grandparents used to do—which is get on the Red Car and go to the ocean.”

When the 6.6-mile line opens, it’ll be the first time rail service has carried passengers to the beach since the 1950s, officials said.

The $1.5 billion extension will stretch the Expo Line from its current terminus near Venice and Robertson boulevards in Culver City to a station at Colorado Boulevard and Fourth Street in downtown Santa Monica. The extension includes seven new stations, including stops in Palms, West Los Angeles and the area just north of Santa Monica College.

When the extension is opened, the Expo Line will stretch from Santa Monica to downtown Los Angeles, ending at the Seventh Street/Metro Center Station at Seventh and Flower Streets. Riders at that station can connect with the Blue, Red and Purple lines, taking them to Long Beach, Union Station, North Hollywood or the mid-Wilshire area.

Metro officials said the ride from Santa Monica to downtown Los Angeles is expected to take 46 minutes.

Metro will offer free rides on the route on May 20 and 21 to introduce passengers to the new line.

Garcetti said he expects the line to be one of the Metro system’s most popular, far exceeding the anticipated passenger count of 30,000 riders per day.

“We think it could be probably 40 to 45 thousand, and my prediction is it’ll go well over 50,000,” Garcetti said. “The nice thing about a train is we can add capacity. We’re running every 12 minutes to begin with, but if we need to run it every 10 minutes or every eight minutes, we can build that capacity as the ridership surges so that you’re never going to be in a crowded car, but you’ll be able to get in there and get where you need to go.”

Along Crenshaw Boulevard, Supervisor Mark Ridley-Thomas, who chairs the Metro board, lauded the halfway milestone and said the 8.5-mile line will have eight stations, with the northernmost connecting to the Expo line and the southernmost to the Green Line. It will serve passengers in the Crenshaw District, Leimert Park, Inglewood, Westchester, LAX and points in between. Thomas also commended the patience of residents and merchants on and near Crenshaw Boulevard who have had to endure considerable upheaval because of construction.

“The communities surrounding this line have endured traffic noise, dust and other nuisances over the past two years, and their sacrifice has not been in vain as we already have a lot to show for it,” Thomas said, adding that construction has been a “community effort” with local stakeholders participating in the development since it’s inception. “The Crenshaw/LAX line is being built by community members, and millions of dollars have been granted to local businesses.”

So far, workers have excavated the Crenshaw/LAX line’s three underground stations beneath Exposition Boulevard (allowing for transfer to the Crenshaw line) and the tunnel boring machine, named “Harriet” after abolitionist Harriet Tubman, has begun drilling a path for trains underneath Crenshaw Boulevard. As well, workers are building bridges that will span the 405 Freeway, La Brea Avenue, Manchester and Century boulevards, and connect the Crenshaw/LAX line to the Green Line along the 105 Freeway. They’ll begin laying tracks later this year.

Funded through Measure R, a half-cent sales tax approved by voters in 2008, the Crenshaw/LAX line is projected to have a daily ridership of 13,000 to 16,000 persons. It would be the first to serve the area since street cars—dubbed “Yellow Cars”—ceased operation in the 1950s.