If you jump, hold a direction, and press c-down right after you jump and press it again right before you land, you will travel much faster than if you were to run, but it's only good for travelling long distances.

but how do i get the game to speed up for no reason what so ever?

sorry for the 3-year late reply. but the answer is in the title screen menu. there is a settings option to increase stick sensitivity and for some reason this allows Batman to move much more quickly. also you can remap buttons for more optimized play in the settings option too.