In CS the only way I found to have even moderately decent traffic flow was to make absolutely every street a one-way street. I don't claim to understand why that helps, but it seems to.
The downside is you have to be very careful where you place your emergency services as you can easily get zones which are too far for firefighters to reach.
The downside is you have to be very careful where you place your emergency services as you can easily get zones which are too far for firefighters to reach.