Use of polynomial transition curves in the design of horizontal arcs

Abstract

The paper presents the use of polynomial transition curves in the design of curved horizontal alignment of roads. The method based on using appropriate families of polynomial transition curves can provide a useful tool for road engineers. The geometry of these curves is defined by parameter C representing the relationship between the slope of tangent line drawn at the point of curvature, the assumed radius at the point of tangency and x-coordinate. With a wide range of C values it is possible to obtain curves with geometry well adjusted to local constraints. This paper provides a brief description of the geometry of such curves. Moreover, it gives formulas for setting out these curves in field.