Enhancing road safety: UAV-enabled warning message dissemination in urban and rural environments for VANETS

Vehicular ad hoc networks (VANETs) safety applications aim to mitigate the growing frequency of daily road accidents. These applications require the prompt dissemination of warning messages among vehicles, regardless of traffic conditions or environment. The limited terrestrial coverage in sparsely populated rural regions challenges the timely receipt of warnings during accidents. To address these issues, integrating unmanned aerial vehicles (UAVs) into VANETs offers a promising solution. UAVs can function as flying relays, meeting necessary delay limitations and overcoming communication problems. In prior work, we introduced a unified UAVs-VANET architecture, using UAVs to relay safety messages among vehicles in rural settings. This paper extends that work by integrating UAVs in rural and urban environments. Our approach includes determining the minimal residual UAV energy needed to connect to a charging station, ensuring continuous UAV operation. This extended framework ensures all vehicles on a 25 km urban highway receive alerts within 1.95 seconds.