CHICAGO (CBS)–The largest and most expensive project in CTA history is moving forward.

The CTA board on Tuesday approved contracts to revamp the Red and Purple Lines and extend the Red Line from 95th Street to 130th Street.

The board awarded Walsh Fluor Design-Build Team with a $1.27 million contract to start the Red and Purple Line modernization project.

It will rebuild stations, track and bridges, and add a Brown Line bypass near the Belmont stop.

The board also approved a $20 million contract to construction management firm HNTB Corporation for the Red Line extension project.

The extension project includes the addition of four new stations and extending the red line down to 130th street.