Not an expert but the speed of light limitation seems to be derived from special relativity considerations the constancy of that speed and the use of light to carry information about events. So a train cannot accelerate to beyond c because of this. But not every phenomenon is limited by this.

As an example if you shine a torch at a really far away rock the dot can move faster than c transversally when you wiggle the torch. But the actual light is going at c to the rock and back to you.