I used to do this with rct3. I put a double monorail station at the standard entrance and then ran the monorail around the edge of the park to the top of the map. People had to use it as there was no other way into the rest of the park. I then used the top of the map as my entrance.
In fairness, some of the peeps didn't like it, and some forgot to get off at the top, but it felt a little bit like Disney to me.