Chicago Transit Authority to begin Red-Purple Bypass construction

CTA President Dorval Carter joined CTA officials and members of the Walsh-Flour J.V. in making the announcement

September 06, 2019
Chicago Transit Authority to begin Red-Purple Bypass construction

The Chicago Transit Authority this week held an event for members of the media to discuss and detail its $2.1 billion Red-Purple Line Modernization project (RPM), the opening salvo of which is expected to get underway this month. The project will involve three phased periods of construction, and is expected to both impact and improve transit service on the Red, Purple, and Brown lines.


The initial phase of construction, which was the focus of discussion, will involve the erection of a bypass track for the Brown line, which at present intersects the track used by the Red and Purple lines near the Belmont Station. This intersection frequently causes delays in service that radiate through the Red Line as it proceeds north toward Evanston. Red and Purple trains have to wait to cross for the Kimball-bound Brown Line trains to come through, and vice versa. The reason behind this bypass project is to eliminate that conflict point. Construction of the 0.3-mile bypass will begin this fall and run through summer 2021, while between summer 2021 and summer 2024, the 100-year-old Red and Purple tracks will be completely rebuilt between Belmont and Cornelia.


Two other main components of Phase 1 will be the modernization of track between Lawrence and Bryn Mawr on the city’s far north side, and overall corridor signal improvements.


CTA President Dorval Carter was on hand as well, and at one point remarked, “I remember when [CTA's Chris Bushell] told me if we don’t find a way to rebuild the Red-Purple line, it’s basically going to fall apart. That led to our journey in asking our legislature to fund a capital improvements project like this. It was a precursor to the creation of Core Capacity, a new capital program, that allowed funding for projects that would increase capacity by a certain percentage.”


The project is being funded in equal parts by federal and state-sourced dollars. CTA estimates that service improvements will measure out at 7,200 passengers per hour (a 30% boost) once the project is completed. Train speeds at the Belmont intersection are also expected to increase by as much as 60%, once the impediment of crossing train lines is eliminated.


“One of the big benefits will be a closed track system where presently there is an open-track one,” CTA’s Chris Bushell said. “Anyone who has tried to walk or carry on a conversation or have a meal beneath an open-track section will understand how much of a benefit this will be.


The bypass itself will be constructed of segmental steel with cast in place PCCP piers, and feature a closed concrete deck. A joint venture of Walsh Construction and Flour will be taking the lead on this portion of that overall RPM project.


“We planned this not just for the immediate future,” Bushell said, “but for the needs 30 or 40 or 50 years in the future. This was designed for a 100-year service life.”