kkysen

4 ms·

1.
by kkysen 1y ago
The latest tech for CBTC uses UWB for train positioning, which has a precision of a few inches.
2.
by kkysen 1y ago
These pictures show level boarding (minimal vertical gap), they just have horizontal gaps. To the extent that there are some small vertical gaps, that is intrinsic to wheels, which change radius over time as the wheel is worn away. The hori
3.
by kkysen 1y ago
Every NYC subway station has had level boarding forever since they were originally built. There can be some horizontal gaps for sure, which they should fix, but it's generally vertically level within the change in diameter of wheels ov
4.
by kkysen 1y ago
The article counts all the off peak and overnight trains, including shuttles. Even out of all of that, only the Franklin Shuttle is 2 cars and will soon be switching to 3 cars.
5.
by kkysen 1y ago
Only the Franklin Shuttle has 2-car trains, and it'll soon be switched to 3 cars since they're replacing the 75 ft cars with 60 ft cars.
6.
by kkysen 1y ago
Labor is by far the largest share of transit operating costs.
7.
by kkysen 1y ago
They already do this on lines with upgraded CBTC signaling. The train runs in ATO (Automatic Train Operation) in which the driver just pushes the start button at each station. So they tried to combine the driver and conductor into one posit
8.
by kkysen 2y ago
There are other real estate grabs through-running could support. Through-running plans often include a Sunnyside Yards station where Metro-North Penn Station Access (PSA) trains from Hell Gate meet LIRR trains to Penn and Grand Central Mad
9.
by kkysen 2y ago
NJT is indeed quite awful with OTP (83%[^1]), train cancellations[^2], reliability[^3], and transparency. However, through-running is also an opportunity for this to improve because, while bad in many ways as well, the MTA is well a class
10.
by kkysen 2y ago
The line at Moynihan has appreciably slowed down Amtrak boarding. Pre-Moynihan, Amtrak boarding at Penn was faster.
11.
by kkysen 2y ago
An extra minute or two can mean a $17 billion expansion, so it matters.
12.
by kkysen 2y ago
I don't think we do either of those errors. Obviously if the C caller does weird stuff, all bets are off, but we don't mutate through `&T`s or not initialize memory. `MaybeUninit` is only used in a few isolated and carefully
13.
by kkysen 2y ago
This is already done in most places, like browsers. But they want to remove the sandbox for performance reasons.