Crossing is Crux
The flow of traffic stops in every crossing. We need more U-turn lanes and roundabouts to keep traffic flowing.
Some cities in the US already have deployed roundabouts and had great success with them. They are a cheap and great solution for the crazy amount of cross-traffic in Miami. The real chalenge will be educating the uneducated drivers in Florida. People who don't sign to change lanes or cross several lanes at once. In the beginning, the roundabouts need to be well signed and with traffic officers along them to keep traffic flowing and educating people.
Another measure is the U-turn lanes instead of crossing traffic. This would work like on-ramps on a highway enabling the traffic to flow and the vehicles to cross lanes to get to their exists.