One Big Bug
. It's not the map's fault! Yes, a higher spec PC with plenty of RAM will certainly help (I have a quad-core with 8gb RAM), but most important is a quality graphics card (€100+). It really is worth the money, as you'll see a huge increase in visual performance. With a low-end card you'll get big FPS drops, especially with heavy AI traffic, and a lot of vehicle lights on screen is another cause.
You'll also get delayed AI spawning. In other words, the more the GPU has to deal with, the slower it functions.
"Lines on the road are visible only 50 m ahead, above they vanish". This is due to a low setting of the Anisotropic filtering - the higher the setting, the more detailed distant objects will appear to be. Again, requires a high-end graphics card to enjoy the best effects.
MandelSoft: So is the Graverly Hill Junction one of your future mapping projects?