In terms of infrastructure construction, plastics and composite materials are mainly used for roadbeds, guardrails for high-demand roads, various traffic signs and signs, rail fasteners for high-speed railways (including mats and baffle seats, etc.), filling materials for rails, Elastic sleepers and other components. In terms of transportation tools, the application of plastic materials is more in the automotive industry, while in locomotives, plastics are mainly used in oil-free lubricating parts, brake disc friction plates, window glass, etc., in other types of transportation vehicles. The use of plastics and composites is also becoming more widespread.