grolby

Yep, exactly. About the best proxy we have (which still isn't very good) is the number of annual licenses issued by USAC each year. And one year to the next doesn't really tell you much; you need three data points to determine a trend. This data is available, though.

I can tell you that participation steadily increased during the time I was racing in Tennessee (2009-2013), with very noticeable increases in field sizes at most events year over year. I don't know what's happening down there this year. I think it's a little premature to be formulating theories for a decline that may not even be real. I certainly believe that participation is down in the Northeast this year, but there are any number of possible explanations for year to year fluctuations in a region where road racing is probably pretty close to its current maximum potential anyway (based on number of road cyclists in the region, exposure, interest in pro events, blah blah blah). What we know for certain at the national level is that road racing is not growing as a sport, but that's old news, really.