What are the vertical supports for guardrails required to consist of?

The vertical supports for guardrails are required to consist of three-inch Schedule 40 steel pipe because this specification ensures the necessary strength and durability needed for the guardrails to withstand impacts and external forces. Steel pipes of this size and schedule provide a robust framework that can effectively prevent vehicles from breaching the guardrail and thus enhances safety on roadways.

Using three-inch Schedule 40 steel pipes also adheres to industry standards typically outlined in safety regulations, ensuring that the guardrails remain structurally sound over time and can handle various environmental conditions and physical stress. This choice minimizes the risk of failure during a collision, contributing to the overall effectiveness of the guardrail system in protecting both drivers and passengers.

Materials such as wooden posts, aluminum pipes, or PVC pipes do not meet the same structural integrity and longevity requirements as Schedule 40 steel pipe, which is why they are not suitable options for vertical supports in this context.