Dial-a-ride problem with goods delivery using drones

Online ordering and delivery of products has grown significantly in recent years. In addition, the transport of people from a desired origin to a desired destination has become increasingly important. We present a novel mathematical model that aims to combine the transport of products by drones with the transport of dial-a-ride customers by people carriers. This novel approach is called the dial-a-ride problem with drones, or DARPD for short. In the DARPD, passenger vehicles that transport dial-a-ride customers are equipped with drones, allowing them to deliver parcels to recipients simultaneously with the passenger transport. The DARPD determines the route for the passenger transport and enables the drone to take off from the desired locations and destinations of the dial-a-ride customers. A drone can independently deliver products to one or more parcel customers. After delivery, the drone returns to the dial-a-ride transport vehicle, where its battery is replaced to make it fully operational again. The strength of this novel concept is demonstrated through a computational study. The results show that combining passenger transport with parallel product delivery by drones can yield significant economic and ecological benefits.