Even if the keyareas may seem to be empty - the whole map looks to messy and filled with actually pointless stuff which isnt necessary for the gamemode you used as a standard for your map.
Too open, boxes at the sides are pointless and what's up with the boxes in the middle of some areas? I mean are we going round cones or something for a drivers test?
Please throw away that grass. Take a look at other dust maps (with at least a like rating over 20, I'll be removing a load soon) and look at how the dust tiles should be properly used. This is very amateuristic.
My opinion is the same as Jite
Maybe you should some varieties to fill up the emptiness of this map, it does look like a fun map to play in. Oh, and the bomb sites should have more than 2 ways to get in at least. It's kinda unfair imo
Honestly tiky. I rate to use any other tileset to create new maps. Secondly like Avo said that there are so big and empty areas. And finally if you want that player can't go under a /e.g. Helicopter, than you put dyn_wall under the sprite anf chose the tile under this one, but i already see on the mapexport that you didn't changed the function to wall without shade. Do this.