I would take away some of those streets that are connected to the 4-lane collectors. That way you don't have a bunch of four-way intersections on your collectors. I would every other street connecting to the collector and remove the opposite street from the other side until you get to the last one, I'd leave that T-intersection. I hope that makes sense.

T-intersections don't cause as much of an issue because they don't have as many left-hand turns as 4-way intersections. The left-hand turns can cause congestion because of the traffic lights. You could also add roundabouts to help with the issue because they eliminate left-hand turns. But they have also have their problems. I hope all that makes sense.