I'm unsure what NAM simulator I downloaded.
I know that it came with the improved subway congestion view; is that simulator Z as Z's thread indicates?
You can check in the Network Addon Mod folder in the Plugins folder for a file that starts with NetworkAddonMod_Traffic_Plugin_... That will be followed by a letter. If the letter is a 'Z', then you do, in fact, have the Z simulator installed.
All the simulators in the current NAM now come with the improved subway view. If you didn't specifically pick a traffic simulator, then you got the default Maxis simulator, which is the worst of them all. (That's why all the other ones were written.) If you don't have a file of the type that CaptCity mentioned, then you are using the default Maxis simulator. If this is the case, I would suggest rerunning the NAM installation (no need to uninstall it first), and pick a simulator under the "Traffic Controller Files" section. As you might expect, I would recommend Simulator Z. ;)
It turned out that I had the C simulator plugin. I switched to Z-Ultra because my RHWs required it.