When it comes to cars, traditional vehicles (driven by natural persons) are no longer the only ones out there since the self-driving cars (where the controls are entirely or partially controlled by a system called automated driving system) have made their entrances. Nowadays, the use of automated vehicles on public road is attracting attention as the legal system to ensure traffic safety is adapting to new types of vehicles. The fundamental laws at the base of the legal system regarding cars and traffic safety is the Road Transport vehicle Act, the Road Traffic Act, and the Law concerning punishment of acts that cause death or injury by driving a motor vehicle. In this chapter, after an overview of the purpose of these acts and regulatory contents, I will focus on the recent legal developments on measures against drunk driving, dangerous driving, and the preparation toward the use of automated cars.