True story, happened to a Trek Across Maine rider, this year, killed him. According to witnesses, the rider was drinking from his water bottle as he was getting passed.

As a general rule I find that the truckers are a lot better (at least on my commute) about giving room when passing. The truck drivers usually pull into the other lane when they pass me, if they can.

The closest I have ever been passed, was a woman in a Subaru. My hand to the gods, she wasn't six inches off my handlebars.