The Los Angeles County Metropolitan Transportation Authority is launching a $350 million project to modernize the Blue Line — shutting down the southern section of the rail for months beginning Saturday.

The massive renovations were announced at a Tuesday news conference attended by L.A. Metro Executive Director Tim Lindholm and Long Beach Mayor Robert Garcia.

The lower section of the Blue Line, which connects downtown L.A. and Long Beach, will be closed from Saturday through late May. In the meantime, a number of shuttles and buses will help riders get through the area, according to Lindholm.

The upper section of the line will be closed from late May through September, officials said.

Improvements being made include an overhaul of all the track work, renovations to signal equipment and train control equipment, new signage and repainting of all the stations, Lindholm said.

But some riders are worried about the massive closure and what it could mean for their daily commutes.

“To me, it seems like its going to be a nightmare,” said L.A. Metro rider Kimberly Thomas. “Hopefully, it’ll be organized so we won’t be late to work.”

“The people who don’t have cars — what are they going to do? How are they going to get to the next point?”

L.A. Metro’s Blue Line is the authority’s oldest rail line, according to industry news magazine Progressive Railroading.