Impact Evaluation of Cyber-Attacks on Traffic Flow of Connected and Automated Vehicles

Connected and automated vehicles (CAVs) can improve transportation safety and efficiency based on vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communications. However, there are potential cyber threats to the communication systems via on-board unit equipped in CAVs and road-side unit. Based on existing traffic flow models, we design an evaluation framework for cyber-attacks on CAVs, and further investigate the impact of proportion of cyber-attacked vehicles, cyber-attack severity, cyber-attack range and traffic demand. Moreover, performance of the transportation system is analysed based on four indicators, including efficiency, safety, emissions and fuel consumption. The numerical simulation results show that with the increase of cyber-attacked vehicles and higher cyber-attack severity, the negative impact on traffic flow gradually becomes notable with lower capacity, higher risk of rear-end collision, more air pollutants and fuel consumption. In addition, it may lead to accidents and inefficient traffic operations if cyber-attacks occur on position rather than speed, and thus the position-attacked traffic system consumes more energy and emits more pollutants. The findings of this study provide useful information for the prediction of future cyber-attacked traffic, comprehensive evaluation of transportation systems, as well as management of automated highway systems from the perspective of network security.