trainz railroad simulator 2006 was released in september of 2005. it had more engines than trainz 2004 and the design was new as well. it came with new routes and some of the old ones from previous games such as: britsh midlands, and outback austrailia. those both had improved version with a 2 next to it. the secind version was bigger, better, and had more to do in them. overall it was almost like reinstalling trainz 2004 but adding a service pack/ expansion pack to the game.