Comment by qwhelan

I've never ridden in Illinois, but yeah:

> § 11-1512. Bicycles on sidewalks. (a) A person propelling a bicycle upon and along a sidewalk, or across a roadway upon and along a crosswalk, shall yield the right of way to any pedestrian and shall give audible signal before overtaking and passing such pedestrian.

https://codes.findlaw.com/il/chapter-625-vehicles/il-st-sect...

No idea if the lakefront trail is classified as a sidewalk but there are at least some cases in Illinois where either a bell or a "on your left" are legally mandatory.