This family consists of access restriction or limitation by natural physical barriers at specific parts of stations to prevent unauthorised access to the rails. It can equally involve shaping the terrain or the vegetation in a particular area in order to enhance the visibility or the movement of people.

It is considered a physical family because it transforms the design of the railway environment by physically cutting vegetation.

Measures in this family are often referred to as: clear cutting, improving the railway environment, environmental design, removal of vegetation, or engineering.