Shadow is surrounded by the military and police after stealing the Chaos Emerald from the federal reserve bank. As he watches them, he has a flashback a running down a hallway on the ARK with Maria. Returning back to the present, Shadow promises Maria revenge against humans.
Throughout the stage there are huge suspension cables of the bridge that Shadow can grind on. Performing tricks perfectly will get you far in this level, as they can allow you to cover great distances and skip large sections. This level has many enemy bots, as well as a few lightning fast (and dangerous) bomber jets.
- Radical Highway (or somewhere similar) is where the opening cut-scene took place in Sonic Adventure 2.
- Radical Highway is filled with snow and used in the Dream Snowboard Cross event in Mario and Sonic at the Olympic Winter Games. Curiously, the NiGHTS cameos in the background were removed and replaced with a neon Chao head. This is probably to keep any non-Sonic or Mario characters out of the game.
- A remixed version of the Radical Highway theme appears in the 2P battle mode of Shadow the Hedgehog.
- Radical Highway is based off San Francisco's Golden Gate Bridge along with other stages.
- By looking at the "Caution!" signs scattered around the level, it's safe to assume that Radical Highway was under construction when Shadow was running through it.
- Since it's a reincarnation of the level, the Generations version is also under construction.
- Big the Cat is seen on a blimp in this stage, only in the Dreamcast version.
- NiGHTS' head can be seen spinning on top of a building.
- Radical Highway's name is similar to Radical City, a course in Sonic R, and Radical Train, and stage in Sonic the Hedgehog (2006).
- There are highway signs in this level saying Amigo in this level, also on a sign on the other side of it, it says "Freedom ? miles". Most likely alluding to the dark story.
- Radical Highway is a stage in the 3DS version of Sonic Generations.
- In Sonic Generations, you play as Sonic the Hedgehog instead of Shadow. However, Shadow is still present in Radical Highway, as the rival battle takes place there.
- The Mario & Sonic incarnation of Radical Highway is the only one to have a different blimp to the others, as the one from M&S literally says "Radical Highway" instead of "Got Ring?" or the Soap logo. The NiGHTS cameos are also removed, most likely to keep the represented series to just Mario and Sonic
- There is a sign that reads" Time Eater" who is the main villain in the game Sonic Generations. The sign only appears in the Sonic Generations version of the stage.
- This stage looks similar to Speed Highway from Sonic Adventure.