Is there any way to close the in-game popup (those that for example says that it's OK to start from a station) from the keyboard? It's a little annoying to have to grab the mouse to press 'close' at the same time you should release the brakes and power up. VidMate
No, there is not. Standard windows will close automatically after a few seconds, scripted html messages will pause the game while displayed.
If it helps you can make all popups pause the game so you don't waste in-game time moving the mouse to close them.