It's a good idea but it may not be possible to implement in NYC. The stations go from full to empty throughout the day. The incentivized routes would change rapidly, and how do you find out about them? It's not like Paris where the uphill stations have empty docks and the downhill stations are full of bikes. There you can ride for free if you go from downhill to the uphill station. I think I read that even that hasn't been sufficient. Not many people are willing to ride up the hill. It's really big and steep. So far, the service area for Citibike in NYC is in the flattish parts of the city. It will be interesting to see what happens when it reaches the hilly parts. Some people don't know it, but we definitely have some real hills.

I'm spending a few days in Florida, and I see Citi Bike in Miami. The models are not the same, and neither is the operating company.