Ummmm, Leroy? Been reading the NY Magazine lately? The system responsible for a third of all US rail transit works like this:
Light Rail Myths and Realities 4943Correct. I simplified to the point of incorrectness. The problem of induced demand is so often discussed that shorthand creeps in. There is a case for induced demand as high...
The weakness of the relays is the wiring that leads up to them, which dates to the thirties and is wrapped in cloth so decrepit that it burns when ignited. Worse, those wires carry a searing 120-volt power supply, ten times more powerful than modern wires. When firefighters showed up to quench the Chambers Street blaze, they couldn't use their hoses because the wiring was still live, and there was no central switch to turn it off. Transit workers had to painstakingly trace each wire back to its source and cut it manually. "Everything is hooked up to everything else. It's an old design," says Tracy Bowdwin, the buttistant chief signals officer. The NYCT has slowly been replacing the stuff, but 41 of 200 relay rooms still use antique wiring. It won't all be gone until 2023.
Reminds me of a argument my dad had 30 plus years ago when his 1920 Buick was being judged. The judges wanted to take off for not his not using cotton insulated wiring as originally installed. He insisted it was a safety issue and touched one of the wires while the car was running. He offered to let any judge who disagreed to touch a cotton wire under the same conditions. He prevailed. Hmmm, do as I do not as I say, he was a pretty smart guy.