In this paper we propose a hybrid heuristic approach for public data delivery under ultra-large-scale smart-city settings. In this approach, public transportation vehicles are going into election process to be utilized as Mobile Couriers (MCs) that read public Access Points (APs) data loads and relay it back to a central processing base-station. We also introduce a cost-based fitness function for the MCs election in the smart-city project which forms a real implementation for the Internet of Things (IoT) paradigm. Our cost-based function considers mobile resource limitations in terms count, storage and energy. Extensive simulations are performed and the results confirm the effectiveness of the proposed approach in comparison to other heuristic approaches with identical objectives.