Resetting the "Frequent routes" drop down list in the training log

Is there any way to reset the "Frequent routes" drop down list in the training log or put a timeout on the list items so they drop off based on the last time a route was run?

I go in cycles for my run routes depending on time of the year, injury rebound, etc., and really don't have a need for most of the run routes currently listed in there.  Be cool to see the list have a user settable option to based not only on frequency but also on recent time period (e.g. last 3 months), or a time period from xx date to yy date .  I could see time period being handy for when I'm training for long run races and I do more of my longer runs during the FL "winter" year after year.  Just a thought...