Hey guys, I have been playing Sim City 4: Rush Hour for quite some time now. Recently, my main city encountered some problem. The demand for residential building is always negative. I have set 7% for their taxes, build extensive subway network throughout the city and sufficient parks, hospitals, fire stations and police stations. Maybe you guys can help me? I do believe it has something to do with the transportation system though.

Attachment 318
This is my main city. The other cities are just feeder cities with small commercial jobs.

Attachment 319
I decided to experiment with the subway networks. I did this and surprisingly the commute time of my city dropped my an all time high of 75 to 45. It remained 45 since then. But it did not change the demand for residential zones. Any ideas on how to improved this?

Attachment 320
This is the entire subway map of my city.

Click image for larger version. 

Name:	Untitled3.jpg 
Views:	202 
Size:	216.1 KB 
ID:	321
And this is the problem I'm talking about.