The curb radius is set at 50'.
This is so strange because the simulation runs fine for about an hour on most of the runs and then one car will hang up and refuse to turn.
I have a situation in SimTraffic where a car is not turning out of a channelized right turn pocket when the signal for the corresponding thru movement is green and there is no traffic blocking the car from turning. The car is just sitting there refusing to move even when it has a clear...
I would try striping first. Add some arrows to your TWLTL if they are not already present; the MUTCD has guidelines for placement. Medians are expensive and limiting access will be unpopular with the public.
It really depends on your objective and what level of planning/analysis you are looking at. Synchro is a macroscopic model and simtraffic is a microscopic model. Take a look at the FHWA Traffic Analysis toolbox; it has a good comparative description that might help you to make a decision about...