Many thanks to all of you. Straight-track seems to have the best solution but at $40 for the detection unit and another $30 for the bell circuit plus flasher lights, crossing gates and gate actuation mechanism I'm probably looking at well over $100 per grade crossing. With the plan to have several protected crossings it gets cost prohibitive .......like $400 for 3 crossings. I was hoping someone would make something like the old Roanoke system......detection, drivers and bell circuit for about $25.....and that was 20 years ago....long before todays great integrated circuit technology. Walthers has a Train-Tronics unit that might work but I can't find much about it and I don't believe they have a website. I guess I'll have to keep looking.