I am trying to mitigate an impact at a signalized intersection along a six lane highway. The higher delays occur with the NB/SB left turns (as far as geometrics go, both the NB and SB left turns are dual lefts). I found that if I change the NB/SB phasing to "split" it reduced the LOS to an acceptable "C". However, I get a warning in the bottom right corner that says "conflicts"...it looks like Synchro is analyzing the intersection as if both the NB and SB movements were to go at the same time, instead of one after the other. Has anyone else had this problem in the past? I have analyzed intersections with split phasing multiple times and I have never run into this problem. Any advice is appreciated.

Thanks