Obviously thos would be impossible to enforce bit I agree with you. Someone should be able to show proof that running is a part of thier daily routine. Carry around a print out of your Athlink results, wear some vaprflies, have a parkrun braclet or something.
Actually around my town its not bad with new runners but entire families out walking witb thier kids taking up the entire trail/path and oblivious to anyone else that may want to to use the path.