Atomic Systems

When a piece of track has a maximum speed limit you're allowed to go .9 mph faster. On a 60 mph track any speed up to 60.9 is still within limits. The only speed at which this appears to be different is 125 mph. Any speed over 125.0 is considered speeding. This isn't much of a problem except when you use the class 390 and want to have the speed "locked" at 125 mph. It tries to keep the 125.0, but the small speed fluctuations cause an almost constant speeding error icon. Is this intended design corresponding to a real life situation, or is it just Railworks with its own AI?

Regards,
Tjeerd