Balancing bike sharing systems (BBSS): instance generation from the CitiBike NYC data

Bike sharing systems are a very popular means to provide bikes to citizens in a simple and cheap way. The idea is to install bike stations at various points in the city, from which a registered user can easily loan a bike by removing it from a specialized rack. After the ride, the user may return the bike at any station (if there is a free rack). Services of this kind are mainly public or semi-public, often aimed at increasing the attractiveness of non-motorized means of transportation, and are usually free, or almost free, of charge for the users. Depending on their location, bike stations have specific patterns regarding when they are empty or full. For instance, in cities where most jobs are ∗Scheduling and Time-Tabling Group, DIEGM University of Udine, Via delle Scienze 206, 33100 – Udine (UD), Italy