That’s the source of a lot of error in project estimates, since it is trivial to come up with plans before considering the details.
Phrasing it as a software project: “I don’t understand why it is so hard to find information on the internet. All of the pages are available through HTTP web servers, aren’t they? What’s wrong with just downloading them all?”
This is a relatively-trivial engineering exercise with any number of safe, efficient solutions. If someone says it will take a billion dollars to solve the problem, that is the person you should demand proof from.
Your comments here are another great example of how ironic it is to hear the word "trivial" used to describe solutions. Don't you think it's a little unrealistic that your "relatively-trivial engineering exercise" suggestions are capable of successfully tackling a problem so many parties have thought about? Have you considered that your insight is actually failing to account for a variety of unknown unknowns you might have about the NYC subway system?
Look at it this way: why do you suppose your suggestions haven't been implemented yet? Do you think the vast array of parties with skin in the game haven't thought of them (and are thus incompetent)? Do you think they simply aren't motivated to implement them?
I wouldn't be surprised if your proposals are technically sound (especially for greenfield rail construction). But I would be absolutely shocked if the problem is anywhere near as trivial as you're making it out to be.
No. Whatever the unknown unknowns are, they're not going to be that hard to work around. Keeping track of a few train cars isn't exactly the Manhattan Project, even if it has to be done underneath Manhattan.
The video suggests that the total budget for the CBTC retrofit was in the vicinity of $1 billion. I hope that I either misinterpreted it, or that the budget includes other improvements, because I doubt it cost that much (in 2018 dollars) to build the initial subway routes in the first place.
Look at it this way: why do you suppose your suggestions haven't been implemented yet? Do you think the vast array of parties with skin in the game haven't thought of them (and are thus incompetent)? Do you think they simply aren't motivated to implement them?
I think the vast array of parties with skin in the game have treated said "skin" as a target for optimization in itself. I'll readily admit they're likely better at that game than I am.
Okay, so maybe you only design a module that can be retrofitted onto existing cars--there's only 16 car designs on the MTA according to Wikipedia. You just have to install them on every car, which means figuring out how to slot the install times into the maintenance schedules of cars, and if your schedule slips for delivering the parts to install, well, that's going to push stuff back a few months.
The problem isn't that the algorithm is hard. The problem is that the hardware didn't exist, and retrofitting hardware is a much more expensive endeavor than retrofitting software.
The cars have to receive power from someplace. Wherever they are being energized, there is by definition a complete circuit to all cars being powered on that line. Likewise, wherever the cars are, there is going to be a large and reasonably well-defined impedance discontinuity on the power rail. So, as a first attempt, I'd look at some sort of reflectometry scheme. Wind a few turns of wire around the cable that feeds the third rail, inject a pulse train with Gold codes or something similar that lends itself to autocorrelation methods, and listen for echoes.
This requires a grand total of $0 in hardware to be added to the cars. If it's not enough -- e.g., if the points raised in Anechoic's post render it impractical to rely on passive reflections -- then it should be possible to add a small amount of hardware at the cars to act as an active transponder, injecting its own pulse train in response to carrier-current signals from the distribution point.
So now we need to connect two wires at each car, and mount a small box with some duct tape^W^W milspec fasteners. Not exactly rocket surgery.
