What materials are primarily used in the construction of escalator steps?

The primary materials used in the construction of escalator steps include steel, plastics, and rubber, which is why this answer is correct.

Steel is commonly used for its strength and durability, providing the necessary structural integrity to support the weight of passengers and the mechanical components of the escalator. Plastics are often utilized for various components due to their lightweight and versatile properties, allowing for efficient manufacturing and maintenance. Rubber is crucial as it provides grip and safety on the step surface, preventing slips and enhancing passenger comfort.

The combinations of these materials ensure that escalator steps are not only resilient and long-lasting but also functional in promoting safety throughout the escalator system. Other material choices listed, such as wood, glass, aluminum, concrete, foam, and fabric, are typically unsuitable for this application due to factors like weight, safety, or lack of structural integrity necessary for escalator operation.