I don't think you can assume anyone is going to use a turn signal. And some don't even angle slightly in the direction of the turn. I drive professionally while doing armed transportation of felons. People don't pay attention to a white official vehicle bristling with antennas, two or more uniformed and badged officers inside, and an official state license with an armed escort behind them! They only care about their own intentions and the cell phone. As I ride home after work, still in uniform I get cut off and have avoided many right hooks. The only thing that seems to help is a flourescent lime green shirt applied over uniform shirt or coat. That and many strobe lights. Take the lane and be visible!