Not gonna lie, some stuff looks off the place to me:
1. The giant tree growing right from the tarmac @ 0:08.
2. The amount of barrels @ 0:26 that could easily be halved with no damage done to the scenery.
3. Not exactly sure why you decided to add the bridge prop @ 0:30. Questionable design decision (and same goes to the next one).
4. What's this giant pile on the right side @ 0:32 and why it's there? I know that this particular area is big and fully open, but you can certainly do better than that.
5. "sub_road" barriers sometimes aiming at the opposite directions while being on the same side of the road (e.g. 0:52 and 0:56, 1:07). Check all of them.
6. Jumps like 1:01 are always nice on paper but be aware that some stock cars (particularly the SUVs and the vintages) may not be able to do the jump due to their mass and acceleration stats.
That's just something I noticed while watching the video once. Don't rush through the map creation process, slow and steady wins the race.