Game Design: Racing Level Pitch

My racing level is set in the ruins of ancient mountain civilization. The high cliffs, unstable buildings, and dangerous defensive traps left by the previous inhabitants make this the perfect location for the death race that the players entered.

Below is some concept images to give an idea about the environment and a colorscheme.

I want the level to be defined by things like narrow roads where the wrong push could send you off the side of the cliff, jumping from old buildings thousands of feet in the air, driving through temples as collapsing pillars fall in your path, old traps left over from the previous inhabitants to stop invading forces. I want players to feel like this is a place where they shouldn't have been racing in the first place, and now have to pay the price.

Which leads to the concept statement: 

"These dying ruins may take you with it"

As for the mechanics of the level, I'd like the level to break down and fall apart more as the laps continue, leaving less room for the player to drive and more danger for them to face. 

Like the Grumble Volcano level of Mario Kart 8 

As the race goes on, parts of the level begin to shake and fall making it a much harder track as the players move to the final lap.

As for stunts and obsticles I had many in mind, things like raising spikes and collapsing pillars, and i'll probably include those someway or another, but for my detailed ones, I settled on these: 

On the left is a pretty basic one, large boulders roll side to side forcing the players to dodge them in order to pass through. I'd like to build off of this, maybe add an incentive to go on the side of the ramp where the boulders would be rolling faster to add some kind of risk/reward, but i've yet to figure it out without breaking the theme. (like a speed boost wouldnt make much sense in ancient ruins) On the right is a jump stunt, because theres no ramp, the player would have to accelerate enough to ride on the side of the cliff, practically horizontally, so that they can make it across to the other side safely.

I was inspired to do these traps based on this scene from The Fast and the Furious, the train part is an example of the same sort of pressure I'd want to put on a player while avoiding the boulders, and the way the car spins in the air after the crash is the same sort of horizontal movement I want the players to have to do in order to make the jump across the cliff

Below are some other sketched ideas

I've also included a map showing how i'd like the track to go. I marked where certain landmarks/points of interest would be. There would also be interior parts of the track, but i felt it would be too confusing to show isometrically. 

All in all, although is a sorta cliche idea, i'm really excited to try it. Ruins archetecture is fun to create and build with, and the traps and obstacles are simple and effective which can really work when you're limited by the time and system you have to build off of.