The terms "guardrails" and "guide rails" are often used in transportation and safety contexts, but they serve different purposes:

1. Guardrails

Purpose: Primarily designed for safety and protection—to prevent vehicles or pedestrians from veering off a road, bridge, or hazardous area.

Location: Installed along highways, cliffs, walkways, and elevated platforms.

Function: Absorbs impact and redirects vehicles to prevent severe accidents or falls.

Design: Typically made of strong materials like steel or concrete, with a focus on crash resistance.

2. Guide Rails

Purpose: Meant to direct or control movement, ensuring vehicles or machinery stay on a predetermined path.

Location: Used in railways, automated systems (like elevators), assembly lines, and some roadways (e.g., lane guidance systems).

Function: Provides physical guidance rather than impact protection (e.g., keeping train wheels aligned or guiding robotic arms).

Design: Often smoother and more precise, sometimes with low-friction surfaces.

Key Difference:

Guardrails = Safety barriers (prevent accidents).

Guide rails = Directional controls (ensure proper movement).