Normally, characters can interact with other characters in nearby zones if they can justify acting at a distance. Super-speed and movement-related power facts provide that justification.
Normally, you can move one zone for free. Super-fast characters should be allowed to move more than this, up to their stated limit, as long as they spend an action to do so. Optionally, the GM can require a successful Overcome roll to reach their intended destination, with failure sending them off course or doing damage (like running into a wall, teleporting into a solid mass, and so forth).
The GM can require a stunt for super-movement through zones if desired, though this should only be done if super-speed is found to be unbalancing.