It works - that's for sure, but it has a lot of it's flaws (as you noticed yourself). I tried my best to complete the road just for the sake of curiosity, but it was nearly impossible due to blocking myself in weird places (eg. when hitting the curb, car jumps off like everything was made out of rubber and then car lands with one wheel on the curb. And that's it, I'm dead cause I can't move xD). It would be cool if you added actual ground next to the road, maybe less stucking and/or falling down will occur.
Also, I don't know if it matters or if I was even supposed to go there, but it's possible to go up the garage at the beginning of the map (by following the arrows), but it's impossible to go down on the other side. Also the gas station should be called "dead station" due to this crazy curb and void behind it. It's fairly easy to get in (as long as you don't fall into the deep abyss of hell), but if there wasn't this crazy jumping-rubber-mechanics it would be impossible to get out of there.
These were my thoughts on the game, do about it whatever you want. It's cool that you're updating it, I wish you success! :)