Profile and stiffness variations along a railway track generate dynamic impact forces on the railway track. A full mechanical evaluation of the interaction between the train and the track is a complex issue due to the presence of many mutually interactive mechanical and geometrical parameters and therefore requires the use of iterative analytical procedures conducted by advanced software. Observations and data collection along a rough length of track where the track profile and/or the stiffness varies, supplement the efforts to understand and evaluate the reasons for and the outcomes of these variations. Nevertheless, the sheer amount of data and the time required for such analysis, along with the complexities of an iterative mathematical evaluation creates difficulties in the assessment of the effects of a rough length of track on the railway services. Engineers, frequently lack the time, the tool or the budget to assess in detail the impact of a roughened length of track on the railway service. Today, the effects of changes in track stiffness and track profile on the impact forces as the track merges into and out of bridges and tunnels and passes over culverts changes due to ballast fouling, rail breakage and track drainage problems are still issues that require practical methods for their evaluation and assessment. To this end, the author developed a set of analytical tools that rely on the principle of conservation of energy, rules of kinematics and a new concept of impact reduction factor. The end result is four equations that can estimate the dynamic impact forces due to ascending and descending track profiles and increasing or decreasing track stiffness values. This paper introduces the fourth equation and provides a thorough and a practical assessment of the findings of the proposed method.

railway track, track profile changes, track stiffness transitions, dynamic impact forces, impact reduction factor, Bezgin Method, Bezgin Impact Factors.