The Chicago Tribune has a lengthy article about the Chicago Lakefront path, and its many hazards:
Ideally, pedestrians and runners stay to the right of each lane near the perimeter or on the soft, gravel-covered shoulder. Faster traffic—cyclists and in-line skaters—travel on the inside, closer to the yellow line.
During these summer evenings, the minefield emerges, and each group blames the others. Sunbathing near the Ohio Street Beach, in-line skater Roger Mroczek turns and points at a child crossing the trail, oblivious to traffic.
I won't ride down the path during peak hours any more. It's not worth it. Even this morning around 8, I almost ran over a portly gentleman shuffling down the center of the path. Because he had his iPod plugging up his ears, he didn't hear me shouting "on the left" repeatedly.
I ride fast, but I'm always aware of everyone else on the trail. I stay right except to pass, which means faster riders can pass me easier. And I have no problem with runners who do the same—especially when they stay on the gravel shoulders or on the new, elevated running path between North Ave. and Oak St.
But my goodness, anyone, whether on a bike, on foot, or—horrors!—on rollerblades, who takes up the entire lane, deserves road rash.