Hügelschäffer Egg Curves as Transition Curves in Road Design

Roads and railways, as the main parts of traffic infrastructure, represent geometrically rigid elements which are hard to adapt to certain kinds of landscapes without making large changes to the terrain itself. Today, thanks to modern technology and a large number of software tools, it is possible to define new geometric curves which are easily adaptable for use as transition curves when designing roads or railways. These transition curves can be formed in such a way to make them fit in with the surrounding landscape or urban environment better, which can improve the aesthetics of the transport system. Furthermore, transition curves provide a smooth and gradual change of curvature, reducing the risk of sudden curvature changes, which can cause discomfort to passengers and create an unsafe situation, such as a loss of vehicle control or a train derailment. Accordingly, in this paper, we define the parameters for generating Hügelschäffer curves as new transition curves between two circular road segments.