Originally Posted by
AlmostTrick
I believe the thought here is that while a lane changer may be changing lanes for any number of reasons, the driver "arcing around" (partial lane change) is clearly avoiding something, so following traffic is more likely to be put on alert.
That could be. Essentially, I think someone would only change lanes if they noticed with a good deal of lead time. But good behavior on part of the lead driver will increase the likelihood of good behavior by the following driver.