Pros: Very large map, and a fair amount of detail added into it. I love the overall design you have with it with having so many bridges, all the ground structures and other stuff on the bridges themselves. Along with that, the buildings fit the map perfectly.
Cons: The colors don't seem to look good with how you put a huge orange box around the map. I know that's what you were going for, but it just doesn't look good.
You also have no lighting, this is a huge down on the scoring for looks and overall gameplay. Shadows are one of the most important parts of making a map look good, with no shadows, the gameplay isn't nearly as good as what it could be.
For the size of the map, you have too much open area. The map is huge but most of it is open ground, this could cause the gameplay to be very annoying becuase you won't be able to get anywhere without getting because of lack of cover.
Improvements: Don't have it as a huge box, cut the box about 1/4 of the way up and make the upper 3/4 the map sky. This will add effect to the map and give it a more realistic feeling.
Put lots of lighting in here, Lighting is very important in every map. There's a lot of areas that should be have shadows in this map, but don't because you have no lights.
Add more cover such as more vehicles, boxes, crates, ect around the open areas of the map to provide more cover for people to run on the ground with.
Notes: Nice start, make a few improvements and it should be much better.