WhichWay

WhichWay · New York City subway · iPhone

Which train, right now.

A subway assistant that reads the MTA’s own feeds every thirty seconds and runs a prediction engine on every train. It names the train to take, counts down to boarding at your platform, and gives the arrival its own 80% window.

  • 30 sfeed cadence, aligned to the MTA
  • 80%window on every arrival
  • 248Kcountdown ETAs benchmarked
  • 21lines calibrated

The app

Everything a platform wants to know.

The screens are the app’s own, captured from the iOS Simulator against the live feeds.

01 / The Now card

Names the train. Counts down to boarding.

The train to take, the countdown to your platform, and the arrival with its 80% window and the feed’s own time beside it. Your commute is already set when you open it.

The Go tab: the Now card names the F, counts down two minutes to boarding and gives the arrival at 14 St with its window.

02 / A train is held

Plan for the hold, not the hope.

When a train on your lines is held, see your arrival if the hold ends as holds here usually do, drags on to its 90th percentile, or clears now. One tap, and every time on screen moves with it.

A held train: the card offers three arrivals, for the hold ending as usual, dragging on or clearing now. The same route with the hold assumed to drag on: every time has moved later.

03 / Every route

Every way there, ranked.

Direct or with one change, ranked by the next live arrival, each with the reason it runs late today and how tight the connection is.

The route list: every way from 4 Av-9 St to 14 St, ranked by arrival, with a health dot and the minutes behind the timetable.

04 / The line

Every train on the track, live.

Your line as a diagram, every train gliding between polls, held and overdue trains coloured, and the engine’s projection for the next hour: the largest gap forming and where.

The Line tab: the F northbound as a track with every started train on it. The same line as a list: each train’s lateness, holds and the engine’s arrival beside the feed’s.

05 / The map and the board

Your stretch, and the trains on it.

The line on the map with the stops you ride, each train where it should be right now; a departure board for your platform with every countdown, flag and change margin; and the hours of the day on this path.

The Map view: the route’s track in Brooklyn and Manhattan with the trains at their positions. The Board view: a departure board for the platform with countdowns to boarding. The Hours view: twenty-four cells per leg shaded by the seconds trains lose at that hour.

06 / Insights

Every number, explained.

Where each time comes from: the timetable, the history, the train in the feed, and what the engine made of it. Nothing on screen is a black box.

Route insights: the sources behind the selected route’s times, one card each.

The engine

Where a time comes from.

The countdown clock runs about half a minute optimistic. WhichWay measures that error, learns how long a held train stays and how lateness carries down the line, blends it all into one arrival with a window, and scores every forecast against what happened.

Every number is from the engine’s published tables and its model report of 5 October 2026. The whole engine runs on the phone, and keeps planning underground.

The film

WhichWay, in a minute.

A run for the train: out of the door, down the street, into the subway and onto the platform as the train pulls in, phone in hand the whole way.

No account

Nothing to sign up for.

Open it, pick a station, go. Your commutes and places stay on the phone.

No signal needed

It keeps planning underground.

Every file it fetches is kept, so it plans from the timetable and the saved tables when the signal goes.

Opt-in sensors

It can learn your pace.

Switched on, the motion sensors learn how long you take to the platform and which train you really boarded. Nothing leaves the phone unless you share it.

WhichWay is in TestFlight.

It runs on iPhone, iOS 17 and later, on the lines the engine has calibrated so far, with more as the record grows. Ask for an invite.