The Network Addon Mod, or NAM, is a modification for SimCity 4 Deluxe (or SimCity 4 with the Rush Hour Expansion pack), which adds a myriad of new transport network items, ranging from ground light rail, to fractional-angle roads, to roundabouts, and much more. It also includes bugfixes to Maxis items and a highly optimized set of traffic simulator plugins, improving pathfinding accuracy and performance.
This review may contain spoilers
This mod is something that turns SC4 into a game that stomps the hell out of most 2011 and later games, due to the the possibilities, the strategy this adds, and best of all, the creativity! From the amazing smooth curves to the realistic ability to make freeway on and off ramps, there are many things this mod makes awesome, even down to micromanaging the direction the signal lights go at each intersection.