NICET - Highway Construction Inspection Practice Exam

What is the minimum thickness required for the top and mid rails of a guard rail?

1. 1/8"

2. 1/4"

3. 1/2"

4. 3/4"

The correct answer is: 1/4"

The minimum thickness required for the top and mid rails of guardrails is established to ensure adequate strength and durability in protecting vehicles and pedestrians. A thickness of 1/4" provides the necessary resistance to impact while remaining lightweight enough for practicality in installation and maintenance. Thicker rails, while potentially offering greater strength, could lead to increased costs and weight, which might complicate installation and design. On the other hand, a thickness any less than 1/4" would not meet safety standards required for effective impact protection, as it may bend or break under stress, compromising the functionality of the guardrail. Thus, the specified thickness of 1/4" strikes a balance between structural integrity and practical use in highway construction.