Be careful how you serve some of your stations. Although putting everything you can get (buses, trains, planes, ships) into one station means that you can handle a large amount of passengers or goods traffic, make sure that you are careful not to take the goodies away that money-generating long route that’s been keeping you going. Sometimes, a few buses can empty a station so that a train can take forever to build up a full load.

See screenshot below:

Bribing costs a lot and sometimes you get found out. Plant many trees around a town to increase your rating if possible.

Press x when ingame to enable or disable trees and buildings transparency. See screenshots below.

Remember to upgrade your bridges as the game progresses. At the start of the game, cheap bridges can suffice and save you lots of money, but once the new, stronger bridges appear there’s no point having a 200mph train having to slow to 20mph to cross a rickety old wooden bridge!