I think this is the area you mean - links: new editor
/ old editor
You need to disconnect Belmont Valley Rd from the highway, and then put the highway back to the shape it was. This really is easier to do in the new editor. I've unlocked some parts of Belmont Circular for you.
Here's a guide that might help: http://www.waze.com/wiki/index.php/Map_ ... _Editor%29
PS: I notice that there are some cross roads that aren't connected. It would be good if you could create junctions here. See Wiki for how to do it in new or old editor.