transition curve

A transition curve, also known as a spiral or easement curve, is used in railway and road design to smoothly connect a straight section to a curved one. It gradually adjusts the turning radius, allowing vehicles to change direction safely and comfortably. Instead of sharp turns, the curve gradually increases or decreases in curvature, reducing sudden changes in lateral acceleration. This design improves safety, comfort, and vehicle stability during travel. Essentially, a transition curve acts as a gentle bend that helps vehicles smoothly transition from straight paths to curves, preventing jarring shifts in motion.