They can, however, hit the brakes as best they can (kinetic energy is proportional to the square of velocity, so this helps a lot), and warn passengers to brace

They can, however, hit the brakes as best they can (kinetic energy is proportional to the square of velocity, so this helps a lot), and warn passengers to brace for impact (example: https://en.m.wikipedia.org/wiki/Glenbrook_rail_accident#Effects https://en.m.wikipedia.org/wiki/Glenbrook_rail_accident#Effe...)