My experience is that many recreational cyclists have no clue about communication with others. The ones that are a part of my club and, thus, ride with accomplished cyclists have learned to communicate. Not all but most. On the R/T there is a great percentage of riders who ride a half-dozen times a year and always on the R/T. These are the people who are truly dangerous. And, the mix of serious cyclists cranking down the path and these people is a catastrophe waiting to happen. I plan my R/T rides for times when no one else is riding.