I started wearing a yellow construction vest a few years ago. I was working my way down the Pacific coast and felt really unsafe at the lack of space on those roads (I recommend not riding that route). I popped into a work safety shop in Eureka, CA and bought a road crew vest. I've taken to using it regularly. It fits over everything and when I don't feel like wearing it, I can strap it conspicuously on my rear rack, or stuff it out of sight in my handlebar bag.