  Rapid urbanization calls for smart traffic management solutions that
incorporate sensors, distributed traffic controllers and V2X communication
technologies to provide fine-grained traffic control to mitigate congestion. As
in many other cyber-physical systems, smart traffic management systems
typically lack security measures. This allows numerous opportunities for
adversarial entities to craft attacks on the sensor networks, wireless data
sharing and/or the distributed traffic controllers. We show that such
vulnerabilities can be exploited to disrupt mobility in a large urban area and
cause unsafe conditions for drivers and the pedestrians on the roads.
Specifically, in this paper, we look into vulnerabilities in model-based
traffic controllers and show that, even with state-of-the-art attack detectors
in place, false-data injection can be used to hamper mobility. We demonstrate a
replay attack by modeling an isolated intersection in VISSIM, a popular traffic
simulator and also discuss countermeasures to thwart such attacks.
