I literally can't build a route or drive a train without the game freezing. The only way to fix it is to close down the entire game, and then when you go back in, it doesn't save what you were doing last.
Since you killed the program, you now need to run a database repair, otherwise freezing will continue to get worse.
If you haven't done it already, you need to disable real-time scanning of your Trainz program and data-folder. Sometimes, antivirus programs are a bit more aggressive and will stop files from loading properly and cause the program to freeze.