From a cognitive mobility perspective, it is essential to develop a culture of safe transportation, which requires knowledge of traffic rules and norms. In Hungary and across Europe, road safety education is a priority, and there is a need for improvement in several areas. To develop cognitive mobility, children and young people must learn about traffic rules and norms from an early age, which are necessary for safe transportation. Our research aimed to gain insight into the level of knowledge of road safety among children and young people. The questions in the online questionnaire related to children’s general knowledge of road safety rules. The survey provides information on the theoretical and practical knowledge of children in different age groups and their sense of safety. The indicators used to measure the road safety knowledge of varying age groups were determined based on the competencies and characteristics of each age group and, secondarily, on the role of children as road users. The research revealed knowledge strengths and weaknesses and, in light of the specific and varying levels of knowledge observed in each age group, highlighted areas for improvement, which can contribute to the development of cognitive mobility.