During the weekends of July 18-20 and July 25-27, Washington/Wabash, Adams/Wabash, Clark/Lake (elevated portion), will be closed.
The construction will begin Saturday at about 2 a.m. and regular operations should resume by 5 a.m. Monday, the CTA said.
Only the Green, Brown and Orange Line trains will operate via the Wells and Van Buren side branches of the Loop Elevated.
Blue Line service will continue to serve Clark/Lake via the subway.
For drivers, State Street will be closed to all traffic (northbound and southbound) from Randolph Street to Wacker Drive from Friday at midnight to Monday morning at 5 a.m.
READ MORE | CTA State and Lake station 3-year closure takes effect | What to know