Have you ever heard about the Royal Mail Underground which used to move mail across London? https://en.wikipedia.org/wiki/London_Post_Office_Railway https://en

Have you ever heard about the Royal Mail Underground which used to move mail across London? https://en.wikipedia.org/wiki/London_Post_Office_Railway https://en.wikipedia.org/wiki/London_Post_Office_Railway A small light railway between large cities makes sense where roads are congested and cannot be expanded.