What does the term "tangent" refer to in road description?

The term "tangent" in road description refers to a straight section of a road. In the context of roadway geometry, a tangent is a straight line that touches a curve at a single point without crossing it. This concept is crucial in road design, as it represents the section of road where vehicles can travel in a straight line without any curvature. This designation helps in understanding the alignment and flow of traffic, ensuring that the transition from curves to straight road sections is smooth for vehicles, which can enhance safety and maintain desired speeds. Understanding this terminology is beneficial for planners and designers, particularly when analyzing the geometric design of transportation networks.