While we're discussing it, does anyone know where to get road-standard rear lights for a bicycle? For riding at nights on streets with cars, I want the bicycle to look like a motorcycle: a pair of yellow flashing 'hazard lights' (because the bike is much slower than the cars), red light(s) that brighten when I brake (actually connected to my breaks - doesn't seem technically hard), maybe functioning turn signals.

It's visible, drivers understand it perfectly, and it's a very mature, well-tested road safety technology (unlike much bike lighting). It seems obvious to me, but I haven't seen it anywhere.