Electric bikes that move between bike share stations may solve the bike-rebalancing problem:
The goal of this research is to derive algorithms directing the vans and trucks that bike-share operators use to shuffle bikes from station to station within a city. Trouble is, rebalancing is a moving target with several layers of complexity. You not only need to predict how many bikes a station will need at a certain time, but you need to minimize the (costly and time-consuming) movement of these vans and trucks—and you need to do it all while the system is in use.
Algorithms aren't the only option. Wald reports that at least one researcher is modeling a system in which driverless bike-share trucks could rebalance stations automatically. Of course, an easier way would be for bike-share systems to use electric bikes that shuffled themselves. But the thought of a bike traveling without a rider does bring up the problem of, you know, balance.
Meanwhile, Chicago's Divvy system will add another 100 or more stations next year, all the way up into Rogers Park and down to the far South Side.