Modern railroads typically have extremely tight restraints on slope. This allows trains to be longer and reduces overall shipping costs. In fact, the desire to

Modern railroads typically have extremely tight restraints on slope. This allows trains to be longer and reduces overall shipping costs. In fact, the desire to make railroads less steep has led Americans to do incredible things, like building the Whittier Access Tunnel (and the port of Whittier at all) to avoid trains going uphill coming from Seward. http://en.wikipedia.org/wiki/Whittier,_Alaska http://en.wikipedia.org/wiki/Whittier,_Alaska https://en.wikipedia.org/wiki/Portage_Glacier_Highway#Anton_Anderson_Memorial_Tunnel https://en.wikipedia.org/wiki/Portage_Glacier_Highway#Anton_... https://www.cookinlethistoricalsociety.org/articles/opening-of-the-whittier-tunnel-1942-1943 https://www.cookinlethistoricalsociety.org/articles/opening-...