Guardrails are categorized based on their design, material, and function. The four main types of guardrails are:

1. W-Beam Guardrails

Design: Made of steel beams shaped like a "W" (for flexibility and impact absorption).

Use: Common on highways and roads.

Function: Redirects vehicles upon impact, reducing crash severity.

2. Thrie-Beam Guardrails

Design: Similar to W-beam but with a three-wave pattern (extra corrugation for higher strength).

Use: Used in high-impact zones (e.g., sharp curves, freeways).

Function: Handles heavier or faster vehicles better than W-beam.

3. Cable Guardrails (Wire Rope Barriers)

Design: Made of steel cables tensioned between posts.

Use: Often on medians or rural roads.

Function: Flexible, absorbs impact, and reduces vehicle damage.

4. Concrete Barrier Guardrails (Jersey Barriers)

Design: Heavy, rigid concrete barriers (sometimes with a sloped shape).

Use: High-traffic areas, construction zones, and bridge separators.

Function: Prevents crossover collisions; used where deflection is unsafe.

Bonus (Specialized Types):

Box Beam Guardrails (steel rectangular beams, used in some regions).

Pedestrian Guardrails (lighter, for walkways and bridges).