Put up a concrete barrier and you won't have to worry about people going in and out. Put up some signs of the far left that posts the fines for crossing the lines. I believe Salt Lake has something like that, and while driving there I noticed no one crossing those lines. But between the 215 and Sahara, I see 15+ people cross. Even some crossing 5 times, just by them self.

Someone needs to notify the NHP and Metro of these rules. I see them breaking them on a daily basis.