Radical Highway Act 1's level layout is mostly made up of straight pathways for Classic Sonic to run along and a large number of slopes that can be used by the player to gain speed quickly by rolling down along them. In comparison to the original Radical Highway, Classic Sonic is able to bop and hop across the highways instead of simply charging forward.
Throughout the Act, the player will encounter spinning barrels that block the path. Instead of using the Somersault to get under them however, Classic Sonic can roll under them by pressing down on and at the same time while running or by using the Spin Dash. The Act also features Horizontal Bars to swing from, upward-going air currents that Classic Sonic can ride, Pulleys, Rockets, and chains of Gun Beetles that can be skipped across with the Homing Attack to reach higher areas. Also, halfway through the Act, the "Got Ring?" blimp that have been following Classic Sonic will move into position so that Classic Sonic can use it to bounce over a wall.
In Radical Highway Act 2, Modern Sonic runs through the Act's corkscrews and suspended highways, much like in Speed Highway. The Act features the original Radical Highway's bridges with their suspension rails that Modern Sonic can grind across. Along the way, the player has to dodge Blue Eagles that are attempting to attack Modern Sonic from midair. Vulkan Fighters also appear, who will float stationary in midair and attempt to shoot Modern Sonic with machine gun turrets. This Act also features many of the same gimmicks that appeared in the first Act, including hidden Rockets that can lead to different shortcuts.
This Act's level layout is constructed like a pseudo-3D environment where different routes are set in-between each other in different layers. This means that, depending on the player's choices, Modern Sonic will either move into the foreground where he will grind on the bridges, into the middle-ground that lead through the middle of the bridge, or into the background where the player can avoid platforming sections.
|052||Die-Hard||Clear Radical Highway Act 1 in 3:00.00 without losing a life!||Art||2000 Illustration|
|053||Ring Collector||Collect 30 Rings in Radical Highway Act 1 in 1:00.00!||Sound||Live & Learn|
|054||Keep the Pace||Grab Time Items and clear Radical Highway Act 1 in time!||Sound||Unknown from M.E.|
|055||Rampage!||Defeat 11 enemies in Radical Highway Act 1 in 0:45.00!||Sound||Throw It All Away|
|056||Stealth Attack||Clear Radical Highway Act 1 in 3:30.00 without defeating enemies!||Art||2001 Illustration|
|057||Special Trial||Defeat 3 Gold Beetles in Radical Highway Act 1 in 2:30.00!||Model||Rouge|
|058||Perfection||Clear Radical Highway Act 2 in 5:00.00 without taking damage!||Art||10th Anniversary Figurine|
|059||Ring Collector||Collect 75 Rings in Radical Highway Act 2 in 1:00.00!||Sound||Toxic Caves|
|060||Keep the Pace||Grab Time Items and clear Radical Highway Act 2 in time!||Sound||Palmtree Panic|
|061||Rampage!||Defeat 15 enemies in Radical Highway Act 2 in 0:30.00!||Art||2002 Illustration|
|062||Stealth Attack||Clear Radical Highway Act 2 in 0:40.00 without defeating enemies!||Sound||Sonic Boom|
|063||Item Collector||Get all Item Boxes in Radical Highway Act 2 in 1:30.00!||Art||2004 Illustration|
|064||Special Trial||Boost through Radical Highway Act 2 in 5:00.00!||Model||Shadow|
The following are the suggested clear times for achieving a high enough score to achieve each Rank:
|Act 1||0:00.00 - 2:00.00|
|Act 2||0:00.00 - 3:00.00|
|Shadow Rival Battle|
- Of all the stages in Sonic Generations, this stage is the only one that Sonic was never playable in from the original game. Shadow the Hedgehog ventured through this stage instead.
- Even though Sonic was never playable in Radical Highway in Sonic Adventure 2 story-wise (he was playable on the multiplayer racing mode), he has been there at least two times: During the intro of Sonic Adventure 2: Battle and Mario & Sonic at the Olympic Winter Games (Dream Snowboard Cross).
- There's a large blimp in this level that says "got ring?", which is a reference to "Got Milk?", like in the original.
- It only appears in Act One however, making Classic Sonic the only one to interact with it.
- The Soap blimp is not present.
- The blimp from the hub world says "got ring?" while the one from Act One says "got rings?".
- In Act Two, there are some ads that say "Chao Soda" "Pizza Sonic 20: Anniversary!" and "Time Eater".
- There are also ads in Act One, although they are pretty well hidden, and the "Pizza!" ad is not present at all.
- The "Pizza Sonic 20: Anniversary!" ad is an updated version of the "Pizza Sonic 2" ad from the original City Escape.
- This is one of the two city levels in the Nintendo 3DS version of Sonic Generations, The other being Casino Night.
- Unlike City Escape, this level features Gold Beetles, and there are in fact more than one (as seen in a mission). In this game, they disappear almost immediately after appearing on-screen. Sonic needs to quickly homing attack them before this happens to reach a higher route.
- The remix for Act 1 was made by Cash Cash, while the remix for Act Two was made by Circuit Freq.
- Cash Cash's remix of Radical Highway Act 1 samples the beat used in their song "Obsessed".
- Despite it clearly indicating that the player must boost through the level, it is possible to complete the Special Trial mission for Modern Sonic without using the boost.
- On a similar note, it's also possible to S rank the second Act without using the boost. This is the only level where this is possible.
- This is the only Nintendo 3DS level in Sonic Generations where Classic Sonic can go into the background and foreground.
- Despite taking place in Radical Highway, the rival battle with Shadow does not reference the intro of Sonic Adventure 2: Battle, unlike its console counterpart.
- There are some signs saying "Route 00 Freedom ? Miles" around the level, just like in the original version of the stage.
- Radical Highway is the only stage on the Nintendo 3DS version to have a rival battle with a rival who went through the stage originally.
|"Radical Highway: Act 1 "Vengeance is Mine - Cash Cash RMX""||Cash Cash||3:25|
|"Radical Highway: Act 2 "Vengeance is Mine - Circuit Freq RMX""||Circuit Freq||2:43|
|"Rival Battle: Shadow the Hedgehog "For True Story (Short ver.) - Circuit Freq RMX""||Circuit Freq||2:20|
|"Rival Battle: Shadow the Hedgehog - Shadow Attack "All Hail Shadow (Short ver.) - Crush 40 RMX""||Crush 40||0:48|
|"Rival Battle: Shadow the Hedgehog - Sonic Attack" Live and Learn (Short ver.)"||Crush. 40||0:48|
|N/A (Hub world)||Jun Senoue||1:18|