Road-railway crossings are a special type of intersection where rail and road traffic meet. This part of the traffic surface accommodates both road and rail transport. Traffic accidents and incidents frequently occur at these intersections, often with serious consequences. In addition, road-railway crossings are sources of various other problems. Specifically, they disrupt the continuity of road vehicle movement and, in some cases, rail movement as well. This disruption results in increased energy consumption, greater environmental pollution, loss of time for passengers and staff, longer deployment times for mobile vehicles, and reduced road capacity. The negative effects also include the costs of maintaining the crossings, as well as expenses related to specific investment projects. The behavior of participants in railway traffic, particularly those in road traffic, has a significant impact on traffic safety at level crossings. At each level crossing, a zone of required visibility is defined. Within this zone, road vehicles must be able to stop safely in front of the traffic sign that indicates the location where the road intersects the railway. This zone is usually determined by regulatory acts. This paper analyzes the method used to define this zone and highlights potential inconsistencies that may significantly affect the practical implementation of regulations.