It was sad for me to read that the roundabout at Coffee and Claratina will eventually become a traffic signal.
I am from Scotland where there are many roundabouts, and they are the best way to keep traffic moving.
I have spoken to many people who hate roundabouts and will actually avoid them. The problem lies in the motorist not being properly trained in how to use them. In the big cities in the U.K., there are roundabouts with four or more lanes going into them and and traffic flows without interruption.
As far as a structure in the center, this should be minimal and the space used for wider lanes in the roundabout.
Try going around some of those roundabouts in Modesto with a 40-foot motorhome and you will see the problem.
The cost of a roundabout would be quite a bit less than the installation of a traffic light and the maintenance would be likewise. I am sure the city would welcome the savings.