Railroads don't need Expansion Joints

Why trains railroads don’t need expansion joints? Just like how temperature affects the length of materials in a predictable way…

… stress also causes materials to change in length (often referred to as strain) in a similar manner.

This principle is crucial in the maintenance of continuous welded rail: by controlling thermal expansion, we can manage stress effectively. Essentially, we can counterbalance one factor with the other.

[Youtube]