https://www.transitchicago.com/lbmm-granville-interlocking-noise-and-alleys/
LBMM Granville Interlocking Noise and Alleys - RPM Construction Activity Notices - News - CTA
Alleys may be intermittently blocked by construction equipment and vehicles, but local access will be maintained.
lbmmgranvilleinterlockingnoisealleys