Gantries have plates attached with a code to identify it from other gantries. The codes, which have different meanings for different authorities, usually state the distance of the gantry from the capital city or its geographical location around a station.

The rail gauge is the inner distance between the heads of the two rails in a rail line.

• A broad gauge is usually 1,600 mm (5 ft 3 in).
• Most of the world's railways use a standard gauge of 1,435 mm (4 ft 8½ in).
• A narrow gauge is usually 1,067 mm (3 ft 6 in).

Where a vehicular road / pedestrian footpath and a rail line cross at the same lever (or same grade).

Grade crossings are commonly referred to as level crossings and they may be passively protected or actively protected.

Alternative to grade crossings are grade separations where bridges over or under the rail line (or tunnels) are employed. 

A greenfield is a site which lacks any constraints imposed by prior work. It is usually a new facility. 

A brownfield is a site with established constraints. It may be an operating, abandoned, idle, or under-used facility.