Abstract. Connected and autonomous vehicles (CAVs) will progressively change the functionality of current transportation systems, promising enhanced safety for all traffic participants. Furthermore, there is a palpable connection between road safety and cyber security breaches, as malicious software could lead to unexpected behaviour of CAVs triggering collisions and causing fatalities and injuries. Therefore, policymakers and stakeholders need to take into account knowledge from both CAV safety and cyber security experts, in order to develop the essential regulations. This chapter attempts to bridge this gap between the two domains by reviewing the state-of-the-art with regards to risk assessment for CAVs and cyber security, the impacts of cyber security on road safety and the corresponding challenges. The main outcomes of this review were that current solutions are solely concerned either with collisions and casualties or with the prevention of cyber-attacks. Consequently, there is still not a reported strong correlation between cyber security breaches and the potential decrease in road safety levels. This should be the focus of policymakers in the near future, so as to develop an holistic policy framework coupling safety and cyber security which will assure a safe and efficient incorporation of CAVs in future transportation systems.