# Advances of UAVs toward Future Transportation: The State-of-the-Art, Challenges, and Opportunities
## 3 State of the Art of Practice and Research
### Current Practice and Research
#### 3.1.7 Future Transportation for Emergency Response and Management  
With the continuous growth of population and number of vehicles, violation of traffic rules and unexpected incidents also increases. Moreover, the transportation system is significantly affected during disasters. The current transportation system would not be responsive enough in a shorter period to handle any emergency circumstances. Incorporating UAVs in the transportation system might reduce the emergency response time. With the real-time emergency response system, the extent of traffic congestion can be reduced. Autonomous UAVs can play a significant role in the regulation of real-time emergency response. Some work has been done to design a UAV-based real-time emergency response system. [PERSON] et al. established a unified framework for a UAV-assisted emergency network [91]. It included both trajectory scheduling and communication network design. The emergency response system can be made more responsive with autonomous UAVs. [PERSON] et al. proposed an intelligent autonomous UAV-enabled solution for the limitations of traffic policing and emergency response systems [57]. Apart from these, UAVs could also be employed in medical emergencies [92].  
Moreover, UAVs have been successfully employed during disasters and post-disaster scenarios for various applications ranging from monitoring hazards such as floods, fires, and landslides, to disaster response, relief, and recovery [93, 94]. Due to their surveillance and sensing capabilities, UAVs enhance the effectiveness of responders. They can also provide the view of disaster-struck areas at low altitudes, which cannot possibly be accomplished by manned aircraft. UAVs are invaluable in search and rescue operations, as they can scan through vast and remote areas with much more ease than humans can [95]. UAVs have been used to deliver supplies and recover hazardous materials. UAVs can be deployed to provide communication capabilities in the cases of destroyed communication channels or damaged transportation infrastructures [93].  
In a recent research work by [PERSON] and [PERSON], a review of the current applications of UAVs in the field of hazards and risks associated with landslides was conducted [96]. An experimental study by [PERSON] et al. examined UAV-assisted transportation in Japan and highlighted the potential uses of UAVs for medical and food supply in disaster-struck regions where transportation efforts by road means are infeasible [67]. [PERSON] et al. proposed a deployment tool for UAV-aided emergency communication networks for disaster scenarios. [70]. [PERSON] et al. developed a UAV-based highway landslide warning and emergency response system [97]. [PERSON] et al. proposed a method that focused on dispatching a minimal number of UAVs to provide reliable communication service in disaster scenarios [69]. [PERSON] et al. simulated mapping of disaster-struck areas by multiple UAVs [68]. Figure 8 represents a scenario of a post-disaster mapping mission undertaken by fixed-wing and multi-rotor UAVs with users and ground control stations in the loop [68].