Okay Fellas, welcome to the real world. One must give credit to the designers of the computer game in that they tried to emulate reality. So, unless you have friends at the FRA, and know the fellas that design the computer games, you are dead in the water. As on the real NEC, you will have to follow the speed limits as they actually exist.
Again, welcome to the REAL world. By the way, do you know how to upgrade the track on your computer game so that it can handle trains travelling at 175 mph ???