A-Train HX

This can be done on any map. It requires $600 million in cash and an unobstructed straight path across the map (no mountains). Open the Project menu, use and to align the Bullet Train path until it is yellow (red indicates it is obstructed and cannot be built there) and press . You then need to wait 128 in game days for the construction to complete. If you are following the road map, this should be done after clearing the first scenario on the first map.