I visited the Polaris shopping area (much bigger than just the mall now)in Columbus, OH this past weekend and I've come to the conclusion that a monorail would be a very effective and "green" solution to visitor flow problems. The area has become very congested with traffic and pedestrians. There's a ton of retail spread out over a wide area. I think it would be best served to have several parking areas and then have the trains carry you to your shopping or entertainment destination. The monorail would be "free" to all users but all items sold at the nearby stores would have a slight markup to pay for the operation and upkeep of the monorail.
Pictured above is a quick bird's eye view of the area I got from Bing.com and painted the rough path I think the monorail should take. Some of the stops include the Hilton Hotel, amphitheater (whatever it is called now), the mall, and the area over by Best Buy, Target, etc. There could be two loops, the larger one going out to the concert venue and a smaller one with the main focus on the mall and nearby shopping.
This is my quick Catia model of the monorail track and support structure.