From Halopedia, the Halo wiki
Redlined It is a medal in Halo: The Master Chief Collection. It is awarded for passing through ten checkpoints within the first minute in Halo: Combat Evolved and Halo 2: Anniversary races. It cannot be gained in air races.
- The medal is unobtainable in matchmaking, as Halo: Combat Evolved lacks a race playlist and the checkpoints in Halo 2: Anniversary are too far to reach in the time limit.
- Redlining means to drive at or above red line speeds.