In this paper, we present an innovative distribution scheme aiming at improving the environmental footprint of companies operating in a city logistics context. More specifically, we investigate the daily operations of a parcel delivery company settled in the urban area of Vienna. We propose a two-echelon distribution scheme where goods are not transported directly from their origin (a depot or a warehouse) to their final destination (end customers), but are initially moved into an intermediate platform (a city hub), from where their final distribution is performed. The city hub is located near the city center, close to the final destination of the goods, allowing for a more efficient and environmentally friendly last mile transport. On the first echelon, trucks transport goods, i.e. parcels, from the depot outside the city to the city hub, where goods are transferred to tricycles, operating on the second echelon between the city hub and the final customers. Tricycles are able to access narrow streets, are not exposed to the problem of limited parking space and decrease the amount of emissions produced through delivery operations inside city centers. However, since not all parcels fit the cargo space of a tricycle, trucks are allowed to visit final customers if these customers require a quantity exceeding the capacity of a tricycle. All parcels are present at the depot in the morning, when the trucks can pickup a certain amount of goods and deliver them to the final customers and the city hub. Being located in the inner-city area, the storage capacity of the city hub is limited, which implies that not all goods can be transported from the depot to the city hub at once. Instead, the trucks are obliged to transfer parcels on the first echelon performing multiple trips, while