The other reason cyclists choose the road is because sidewalks are frequently filled with turn-ins and turn-outs. So riding on a sidewalk, even if there were no

The other reason cyclists choose the road is because sidewalks are frequently filled with turn-ins and turn-outs. So riding on a sidewalk, even if there were no pedestrians, would be an act of putting yourself in exactly the place motorists rush to get to/from most frequently.