On my ride home last night I experimented. Riding in a bike lane, near the stripe, about 15 mph (slight upgrade) I was watching in my mirror traffic go by on my left at about 40. They were following a line a few feet from the BL stripe, not adjusting for my presence. I started zig-zigging. I would zig from about the center of the bike lane to the stripe, back and forth. Nothing wild. Really, just smooth constant "S" curves. Immediately the traffic behind me responded by moving a few feet left, closer to the left edge of their lane. It was like a dance.