try to keep your pathway easy to navigate, try to follow a square-like pattern. It not only keeps your quests from getting lost, it also makes it easier for staff to get around.
Also, if you have any buildings, make sure there's easy ways to get out of them. During my time playing the park I just finished, many times mechanics would be in buildings and not find their way out, so I'd have make another path.
Other then that, just more mechanics will help.