  Intelligent transportation systems (ITS) have gained significant attention
from various communities, driven by rapid advancements in informational
technology. Within the realm of ITS, navigational recommendation systems (RS)
play a pivotal role, as users often face diverse path (route) options in such
complex urban environments. However, RS is not immune to vulnerabilities,
especially when confronted with potential information-based attacks. This study
aims to explore the impacts of these cyber threats on RS, explicitly focusing
on local targeted information attacks in which the attacker favors certain
groups or businesses. We study human behaviors and propose the coordinated
incentive-compatible RS that guides users toward a mixed Nash equilibrium,
under which each user has no incentive to deviate from the recommendation.
Then, we delve into the vulnerabilities within the recommendation process,
focusing on scenarios involving misinformed demands. In such cases, the
attacker can fabricate fake users to mislead the RS's recommendations. Using
the Stackelberg game approach, the analytical results and the numerical case
study reveal that RS is susceptible to informational attacks. This study
highlights the need to consider informational attacks for a more resilient and
effective navigational recommendation.
