Per the Traffic Signal Coordinator: The problem is not with 4th St & 6th Ave S, but 4th St & 5th Ave S. For years the intersection at 4th St & 5th Ave S was coordinated southbound with the rest of the intersections on 4th Street, as well as eastbound with the intersections on 5th Ave S (Dali Blvd). However, someone in the City or the Florida Dept of Transportation decided a northbound on-ramp was needed at 4th St & Dali Blvd and so one was installed. Given the situation I was left with after the ramp addition, the best option I could come up with was to let the intersection run independently with the other intersection (4th St & 6th Ave S). I apologize for any inconvenience this may cause. If I can think of a better solution, I will definitely give it a try.

See comment from Traffic Signal Coordinator.