New map from a fan
The author advises on Steam Disccussions there is "a little lag when you looked down two roads in the map. If your all skilled with SDK and can fix it be my guest and send it back to me. Ill put your name on it with a nice thank you and upload an update!"
Source files are included in the archive.
To install simply dezip the content in "steam\SteamApps\common".