What is a grade crossing?

A grade crossing is specifically defined as the point where a highway intersects with a railroad track at the same elevation, meaning both modes of transport share the same level. This can lead to potential conflicts between vehicular traffic and trains, which is crucial for understanding safety measures needed at these locations, such as warning signals and barriers.

The other scenarios mentioned, such as highways intersecting at angles or over bridges, relate to different types of intersections and crossings but do not encapsulate the unique characteristics and safety considerations associated with grade crossings. Understanding the nature of grade crossings is essential for traffic engineering and safety assessments because they pose distinct risks that require specific design and operational strategies to mitigate.