personally i dont think there is a single "fair" solution to the problem. most terrain parks have signage at the top and they still do not keep people out, most people, especially these "gapers", wont take the time to read a sign even if its directly in front of them, for example the singage on how to board a lift, closed trail signs, ect.
i do agree that park passes are in a sense unfair. free park passes shouldnt be a problem though. maybe a good solution would be to have a stamp on the lift tickets that validates park usage so someone could check at the park entrance, all they would have to do at the ticket window is ask 5 quick and easy questions that outline the basics of park riding, and if a person shows to have some sort of knowledge they get the stamp
oh, and blue gets avalanches on the double blacks?