pezz and xenoargh, you guys are right but I forgot to mentioned that this project was a contract for another company. This company needed the 3D model for that part of the city, with all the materials, lights, etc, because they needed put this “game” into a Car simulator, I mean, this “game” will be in front the car windshield and all the controls will be handled with the real steering wheel and the pedals, and that´s why in the “game” there isn´t a visible car. The other company sent me a basic script that allow me drive into the scene to see how the model will work, but the final script for this car was adapted to the real simulator and works very good.
xenoargh, about the traffic, the other company who has programmers (I am an architect), they put the traffic and people routines, the same in the traffic lights, but this final version isn´t mine, so I only could post what I have done (the model, texturing, lighting and Unity3D Integration)
xenoargh about the vegetation, you are right, the vegetation looks very repetitive and only needs a few tweaks to solve like you said (rotate some planes or scale a bit into a random process), but this kind of works all ways need more time that the client has, so I had to do as much as I could within the time the client gave me, maybe when I have some spare time, I will improve the quality.
runner, thanks for your comment, this level was done in two months all by me, I do everything you see here, I been in the real place and I had to film the route. The model was done in 3ds max. The textures was done in photoshop and I created some textures based on the real buildings. The lighting was done in unity3D
Btw, I am from Colombia, so my English is not the best 
Best regards,
Juan Camilo Alcaraz C
www.camiloalcaraz.com