In cyberspace, light-speed circuits appear as straight red lines, often with orange energy circuits running next to them. When coming into contact with one in cyberspace, the users will be transmitted as electron particles, allowing them to traverse at high speeds. According to Shadow, using the light-speed circuit gives a sensation of weightlessness.
Light-speed circuits appear exclusively in Digital Circuit and Mad Matrix. Using them in gameplay allows the players to take several alternate paths to other sections of the Stages that will provide them with Rings and power-ups. There are also often firewalls on these circuits that will try to block the players' paths. To use a light-speed circuit, the player must step on a red/orange hexagon-shaped flashing spot to enter it. Once inside, the player will move along the circuit forward automatically at high speeds. The player can guide Shadow to turn left or right when traversing through intersections or forked paths by moving the control stick in said direction. The player will eventually exit the light-speed circuit depending on the path they took.
In Mad Matrix, there are several Black Arms bombs set up across a maze-like light-speed circuit section which the player must detonate by passing by them in order to complete the Dark Mission.
- Sonic Team (November 18, 2005). Shadow the Hedgehog. PlayStation 2. Sega. Area/Level: Digital Circuit. "Rouge the Bat: This is a light-speed circuit. Touch it, and your body is transmitted as electron particles."
- Sonic Team (November 18, 2005). Shadow the Hedgehog. PlayStation 2. Sega. Area/Level: Digital Circuit. "Shadow the Hedgehog: What is this sensation?! I feel weightless atop this light..."