Start with understanding the problem
Changing the railway means making a system change. This framework will provide you with some tools to help you navigate that more easily. The degree of complexity and interfaces involved may not always be immediately obvious.
These videos give a good overview of the areas that you may need to consider. This framework will help work through addressing the complexity of system changes.
Understanding which aspects need consideration helps develop ideas at an early stage when the problem is often conceptual and filled with uncertainty. There may also be multiple ways to solve the problem with each of those carrying different levels of cost, risk and reward. It is useful to understand that there is a first principles sequence to making changes to the railway system and also that system changes in the early stages can be iterative in their nature.
This framework will help work through addressing the complexity of system changes.