Blue Line riders should find a cleaner subway tunnel Monday morning through which to ride the new 5000-series prototype train cars.
The new cars with aisle-facing seats will shift from the Green Line to the Blue Monday morning. That’s after the CTA completes subway cleaning on the Blue Line overnight on Friday and Saturday. Trains will operate on the same track between Grand and LaSalle stations from 10 pm till 4 am each night. All riders must board and exit trains from the northbound (to O’Hare) side of the platform.
Here’s a CTA video on features of the new Series 5000 rail cars.