I have tested MTH, Williams, and Industrail Rail "O" guage trolleys on SuperStreets with these results:
1 - MTH PCCs and double truck Brills will turn on both D16 and D21 track even without the staight to curve transition track.
2 - Williams Peter Witt will turn running forward on both D16 and D21 without transition track. Running
backwards it may derail on D16. ( I think because the motor resides in the rear truck.)
3 - Industrial Rail trolleys will turn on D21, but not D16. They can be made to turn on D16 by severing
a screw which restricts the turning motion of the truck. (Removing the screw by dis-assembly
involves too much work.)
