My personal experience is that enough folks move over at the last possible second that there is no way to know if the are going to move over until it is too late to hit the ditch anyway. I have to wonder if the majority of the people who have made a dive into the ditch were really going to be hit. I suspect that two negative results come from these dives into the ditch. First the offending parties are probably entertained and find it hilarious and second they start to assume other cyclists will do likewise, making them a bigger danger to cyclists they will pass in the future.

My personal approach is to stay as far right as possible in any situation where taking the lane is not called for. When doing this I try to ride a steady and predictable path. There are times that I leave the road in a pinch situation, but it is never a last second hitting of the ditch.

In my 55 years of bicycling I have had contact with a few cars and trucks. I have been lightly brushed many times, had a car make fairly hard contact while brushing against me, been right hooked and had to throw a shoulder into the car to make an unplanned turn, and once I hit a car that pulled out in front of me. The last was the only one that resulted in injury and bike damage (I got an ambulance ride from that one). The one that brushed me pretty hard had damage to their car in the form of a good bit of trim ripped off of the car and probably a good scrape from the end of the bar and the pedal spindle, but they still sped away weaving and obviously drunk. That time the end of my left pedal was scraped as was the end of the bar and bar tape. By body was completely unscathed.