Originally Posted by
FBinNY
You may disagree, but not only is it common sense, it's the law in many states. When riding two or more abreast, cyclists should make an effort to create passing opportunities by merging to single file, and as I said many states require it.
I think most states say "may not ride MORE than two abreast." Some may say single file. I've seen a LOT of people misread this as "may not ride two or more abreast" though.
It doesn't take any more effort for a car to pass two abreast cyclists in situations where in-lane safe passing is not possible than it does to pass single file. Unless turning the wheel another 10 degrees for 2 seconds counts as more effort.