Gene,
Do you have a copy of The DCS O Gauge Companion, either the 1st or 2nd edition? If you do, look at the section on subways and trolleys. I guarantee it will provide all of the answers you are seeking.
This and a whole lot more is all in "The DCS O Gauge Companion 2nd Edition", now available for purchase as an eBook or a printed book from MTH's web store site! Click on the link below to go to MTH's web page for the book!