There isn't any secret "do not be a moron" hand signal or secret magic ray. Take the lane, be ready to ditch if they encounter on oncoming car and decide to take you out instead of hitting head-on. I've nearly witnessed a head-on myself - the guy in the sports car that had to swerve very fast to avoid the large truck coming over the blind hill he'd passed me on very nearly lost control, and was fishtailing for a couple hundred feet before he got it under control again. What are you gonna do?
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Work: the 8 hours that separates bike rides.