I've noticed two strange issues with this mod:
First, firetrucks seem to exhibit a strange behavior when passing though them. It is as if they are a bus pulling into the station. They stop, about half a block before they get to the fire, and then dissapear.
Second, When I place them atop one-way streets, a lot of the time it will change the direction that segment of street was pointing in. I align the arrow on the lot properly in the direction of travel of the road, but that doesnt seem to matter. It seems to leave E->W roads alone, and change W->E roads to the other direction.
Anyway, I dont know if there's anything to do to fix them, but I'd be interested to see if you can duplicate these issues.