G Gtrained · Updated 0s ago (auto 30s)
G

Bedford–Nostrand

Safe forecast: 100% on-time catch (±18s) · Official: ±54s error

Destination Safe Forecast Official
Court Sq
Queens-bound
4m 10s
then 14m, 18m
3m 41s
then 14m, 17m

Currently at Fulton St (3 stops away) — MTA clock is 22s faster than track speed from Fulton St. Includes 12s early-arrival safety guard.

Church Av
Brooklyn-bound
0m 43s
then 7m, 15m
0m 50s
then 7m, 15m

Currently at Myrtle–Willoughby (1 stop away) — slowing slightly over recent updates (+9s); MTA clock is 43s faster than track speed from Myrtle–Willoughby. Includes 12s early-arrival safety guard.

F

Astoria Ferry

Safe forecast: 100% on-time catch (±16s) · Official: ±55s error

Pier & Direction Safe Forecast Official
Navy Yard → 34th St
Northbound to E 90th St
34m 14s
then 72m
33m 49s
then 72m

Boat H214 finishing prior southbound leg: approaching brooklyn navy yard (10 kts) — Upstream Pier 34 slip traffic (+19s); Terminal crew turnaround buffer (+15s); 3 upstream pier stops (+15s boarding). Includes 15s early-boarding safety guard.

34th St → Navy Yard
Southbound to Wall St
52m 50s
then 111m
51m 40s
then 110m

Boat H092 finishing prior northbound leg: docked at east 34th st (0 kts) — 2 boats near Pier 34 slips (+35s docking wait); Against East River tidal current (+15s); Terminal crew turnaround buffer (+15s); 4 upstream pier stops (+20s boarding). Includes 15s early-boarding safety guard.

G Train — Official vs. Safe Challenger Forecast

Live comparison for Bedford–Nostrand (Stop IDs G33N & G33S)

Safety Guard: -12s early buffer · 10s stability lock
Destination Current Location Safe Forecast Official MTA Adjustment Why It Was Adjusted
Court Sq (N) Fulton St (3 stops away) 4m 12s (03:55:21 PM) 3m 43s (03:54:52 PM) +29s Currently at Fulton St (3 stops away) — MTA clock is 22s faster than track speed from Fulton St. Includes 12s early-arrival safety guard.
Court Sq (N) 7 Av (9 stops away) 14m 36s (04:05:45 PM) 14m 22s (04:05:31 PM) +14s Currently at 7 Av (9 stops away) — MTA clock is 78s faster than track speed from 7 Av. Includes 12s early-arrival safety guard.
Court Sq (N) Fort Hamilton Pkwy (11 stops away) 18m 36s (04:09:45 PM) 17m 56s (04:09:05 PM) +40s Currently at Fort Hamilton Pkwy (11 stops away) — making up time on clear track (-19s); MTA clock is 94s faster than track speed from Fort Hamilton Pkwy. Includes 12s early-arrival safety guard.
Church Av (S) Myrtle–Willoughby (1 stop away) 0m 45s (03:51:54 PM) 0m 52s (03:52:01 PM) -7s Currently at Myrtle–Willoughby (1 stop away) — slowing slightly over recent updates (+9s); MTA clock is 43s faster than track speed from Myrtle–Willoughby. Includes 12s early-arrival safety guard.
Church Av (S) Nassau Av (5 stops away) 7m 33s (03:58:42 PM) 7m 16s (03:58:25 PM) +17s Currently at Nassau Av (5 stops away) — MTA clock is 69s faster than track speed from Nassau Av. Includes 12s early-arrival safety guard.
Church Av (S) Court Sq (8 stops away) 16m 01s (04:07:10 PM) 15m 51s (04:07:00 PM) +10s Currently at Court Sq (8 stops away) — waiting at Court Sq terminal before dispatch (+24s). Includes 12s early-arrival safety guard.

How the Two Subway Forecasts Work (Assuming Zero Prior Knowledge)

A step-by-step explanation of where the numbers come from and why the official clock can make you miss your train.

1. How the Official MTA Clock Works

Subway tunnels do not have GPS. Instead, the tracks are divided into electrical sections called track circuits. When a train’s wheels touch a section of rail, it trips a sensor telling the MTA which station block the train is in.

To guess when the train will reach Bedford–Nostrand, the official MTA feed simply takes the train’s last touched sensor and adds a fixed timetable run-time.

Where it fails: (a) If a train is still parked at the Court Sq or Church Av terminal waiting for a crew, the MTA just shows the printed schedule. (b) At major transfer stops like Hoyt–Schermerhorn (A/C) or Metropolitan Av (L), conductors hold the doors extra long. (c) When a delayed train hits clear track, it can speed up and arrive 20–30 seconds earlier than the official clock says—causing you to miss it.

2. How the Safe Challenger Forecast Works

Instead of trusting the raw timetable, our Challenger model watches every G train every 10 seconds and applies 5 real-world corrections plus two commuter protections:

  • Never-Miss Safety Guard (-14s): Missing a train is much worse than waiting 15 seconds on the platform. The model intentionally aims 14 seconds early when a train is moving so the doors never close in front of you.
  • Anti-Jitter Stability Filter (10s lock): Official MTA times often bounce back and forth by ±20 seconds every poll. Our filter locks the countdown unless the train’s true pace shifts by more than 10 seconds.
  • Terminal, Tunnel & Transfer Checks: Automatically adds realistic wait times for unassigned terminal trains, Newtown Creek tunnel signals, and A/C or L train transfer crowds.

Astoria Ferry — Official vs. Safe Challenger Forecast

Brooklyn Navy Yard (Pier 120) & East 34th St (Pier 34)

Pier 34 busy: 2 boats (2 docked, 0 approaching · +35s queue)
Pier & Direction Vessel Safe Forecast Official Feed Adjustment Live River & Slip Status
Navy Yard → 34th St H214 34m 14s (04:25:25 PM) 33m 49s (04:25:00 PM) +25s Boat H214 finishing prior southbound leg: approaching brooklyn navy yard (10 kts) — Upstream Pier 34 slip traffic (+19s); Terminal crew turnaround buffer (+15s); 3 upstream pier stops (+15s boarding). Includes 15s early-boarding safety guard.
Navy Yard → 34th St Blk 41 72m 36s (05:03:47 PM) 72m 49s (05:04:00 PM) -13s Scheduled (05:04 PM) — steady river speed with 15s early-boarding safety guard.
Navy Yard → 34th St H092 112m 13s (05:43:24 PM) 111m 49s (05:43:00 PM) +24s Boat H092 finishing prior northbound leg: docked at east 34th st (0 kts) — Upstream Pier 34 slip traffic (+19s); With East River tidal current (-15s); Terminal crew turnaround buffer (+15s); 4 upstream pier stops (+20s boarding). Includes 15s early-boarding safety guard.
34th St → Navy Yard H092 52m 50s (04:44:01 PM) 51m 40s (04:42:51 PM) +70s Boat H092 finishing prior northbound leg: docked at east 34th st (0 kts) — 2 boats near Pier 34 slips (+35s docking wait); Against East River tidal current (+15s); Terminal crew turnaround buffer (+15s); 4 upstream pier stops (+20s boarding). Includes 15s early-boarding safety guard.
34th St → Navy Yard H214 111m 59s (05:43:10 PM) 110m 49s (05:42:00 PM) +70s Boat H214 finishing prior southbound leg: approaching brooklyn navy yard (10 kts) — 2 boats near Pier 34 slips (+35s docking wait); Against East River tidal current (+15s); Terminal crew turnaround buffer (+15s); 4 upstream pier stops (+20s boarding). Includes 15s early-boarding safety guard.
34th St → Navy Yard Blk 41 147m 41s (06:18:52 PM) 146m 49s (06:18:00 PM) +52s Scheduled (06:18 PM) — 2 boats near Pier 34 slips (+35s docking wait); Against East River tidal current (+12s); 4 upstream pier stops (+20s boarding). Includes 15s early-boarding safety guard.

How the Two Ferry Forecasts Work (Assuming Zero Prior Knowledge)

How boat GPS, East River currents, and Pier 34 slip queues affect your departure time.

1. How the Official NYC Ferry Feed Works

NYC Ferry boats broadcast their GPS coordinates and a basic delay number through a system called Connexionz. However, the official countdown only looks at the boat’s current trip leg and assumes normal river speed and an empty slip at the pier.

Where it fails: East 34th St (Pier 34) is shared by four different ferry routes. When two or three boats arrive at once, incoming boats have to wait in the river for a slip to open. Also, when a boat is still finishing its previous trip to Wall St or E 90th St, the official feed often shows the printed timetable instead of the boat’s real turnaround time.

2. How the Safe Challenger Ferry Forecast Works
  • Pier 34 Slip Traffic Radar: Counts every ferry across all routes within 0.65 miles of East 34th St to predict slip waiting time before the boat docks.
  • Live GPS Speed & River Current: Uses the boat’s actual speed in knots, distance in miles, and the East River tidal cycle (flood vs. ebb tide).
  • Early-Boarding Safety Guard (-16s): Ferry deckhands pull the gangway shortly before departure. Our forecast includes a 16-second early safety margin so you never reach the pier as the gate closes.

G Train (Bedford–Nostrand) — Official vs. Safe Challenger Backtest

Compares forecasts locked 2–15 minutes in advance against actual departure times.

⬇ Download CSV (20 rows)
Safe Catch Rate (No Miss)
100%
vs 80% Official (4 missed)
Average Error (MAE)
±18.0s
vs ±53.6s Official (+35.6s better)
Forecast Stability (Jitter)
±2.4s
vs ±18.1s Official jump/poll
Self-Learning Calibration
Gen 5
Guard: -12s · 20 verified trips

1. Error by Forecast Lead Time (How Far Back You Look)

Tested at three look-ahead windows before actual departure. Lower bars = more accurate.

10–15 min before arrival (Long Range) ±6.5s Safe vs ±58.5s Official
Safe
0% missed
Official
0% missed
5–10 min before arrival (Decision Window) ±11.2s Safe vs ±47.5s Official
Safe
0% missed
Official
12% missed
2–5 min before arrival (Platform Approach) ±38.5s Safe vs ±56.8s Official
Safe
0% missed
Official
50% missed

Even 10–15 minutes before arrival, Safe Forecast cuts average error from ±58.5s down to ±6.5s.

2. Does Backtesting Improve the Forecast Over Time?

Yes — every verified departure updates tree weights and the early-arrival safety guard.

0s 15s 30s 45s Official (±54s) ±29.4s Gen 1 ±18.1s Gen 2 ±11.4s Gen 3 ±7.6s Gen 4 ±18.0s Gen 5

How it learns: Whenever a train departs earlier than predicted, asymmetric pinball loss shifts the safety buffer earlier by 4× the step size, driving missed trains from 18% in Gen 1 down to 0% today.

Verified Backtest Log — Official vs. Safe Challenger

Negative error (e.g. -6s) means you arrived on the platform 6 seconds before the doors closed (Safe). Positive error (>+8s) means a missed train.

Direction Forecast Lead Time (How Far Back) Official ETA Safe ETA Actual Dep Official Err Safe Err Outcome
Church Av 8m 38s before arrival 03:44:13 PM 03:44:35 PM 03:48:02 PM -229s -207s +22s closer
Court Sq 8m 38s before arrival 03:47:07 PM 03:47:11 PM 03:48:02 PM -55s -51s +4s closer
Court Sq (N) 12m 20s before arrival 02:03:10 PM 02:04:18 PM 02:04:24 PM -74s -6s +68s closer
Court Sq (N) 6m 50s before arrival 02:09:16 PM 02:10:18 PM 02:10:24 PM -68s -6s +62s closer
Court Sq (N) 3m 05s before arrival 02:16:48 PM 02:16:19 PM 02:16:24 PM +24s (Missed) -5s +19s closer
Church Av (S) 13m 10s before arrival 02:20:22 PM 02:21:16 PM 02:21:24 PM -62s -8s +54s closer
Church Av (S) 6m 20s before arrival 02:27:33 PM 02:28:19 PM 02:28:24 PM -51s -5s +46s closer
Church Av (S) 2m 50s before arrival 02:33:02 PM 02:33:20 PM 02:33:24 PM -22s -4s +18s closer
Court Sq (N) 11m 50s before arrival 02:30:20 PM 02:31:18 PM 02:31:24 PM -64s -6s +58s closer
Court Sq (N) 7m 40s before arrival 02:36:26 PM 02:37:18 PM 02:37:24 PM -58s -6s +52s closer
Court Sq (N) 3m 15s before arrival 02:42:53 PM 02:42:18 PM 02:42:24 PM +29s (Missed) -6s +23s closer
Church Av (S) 11m 30s before arrival 02:49:32 PM 02:50:18 PM 02:50:24 PM -52s -6s +46s closer
Church Av (S) 6m 00s before arrival 02:55:48 PM 02:56:19 PM 02:56:24 PM -36s -5s +31s closer
Court Sq (N) 5m 50s before arrival 02:58:50 PM 02:58:18 PM 02:58:24 PM +26s (Missed) -6s +20s closer
Court Sq (N) 2m 40s before arrival 03:02:43 PM 03:02:19 PM 03:02:24 PM +19s (Missed) -5s +14s closer
Church Av (S) 12m 10s before arrival 02:59:29 PM 03:00:17 PM 03:00:24 PM -55s -7s +48s closer
Church Av (S) 7m 00s before arrival 03:05:45 PM 03:06:19 PM 03:06:24 PM -39s -5s +34s closer
Court Sq (N) 3m 30s before arrival 03:15:06 PM 03:15:20 PM 03:15:24 PM -18s -4s +14s closer
Church Av (S) 12m 00s before arrival 03:21:40 PM 03:22:18 PM 03:22:24 PM -44s -6s +38s closer
Court Sq (N) 6m 30s before arrival 03:29:37 PM 03:30:18 PM 03:30:24 PM -47s -6s +41s closer

Historical Misses, Near-Misses & Model Audit Log

Every past miss, caught official miss, or tight margin (≥-4s) is logged with its 5-tree telemetry, root cause, and proposed rule update.

⬇ Export Misses Log (CSV)
Historical Challenger Miss Court Sq (N) · 6m 40s before arrival (4 stops away) (Gen 2 (Pre-Guard))
Official: +34s · Safe: +14s
T1 Term: 0s · T2 Beacon: +18s · T3 Drift: 0s · T4 Seg: +16s · Guard: 0s
Root Cause: Delayed northbound train made up 20s on clear track between Fulton St and Classon Av while Gen 2 had no early-arrival safety guard.
Applied Fix: Introduce -14s asymmetric early-arrival safety guard (4x pinball penalty) and cap Hoyt transfer dwell when train is >60s behind schedule.
Historical Challenger Miss Church Av (S) · 4m 50s before arrival (3 stops away) (Gen 3 (Pre-Deadband))
Official: +27s · Safe: +11s
T1 Term: 0s · T2 Beacon: +22s · T3 Drift: 0s · T4 Seg: 0s · Guard: -6s
Root Cause: Stale track-circuit beacon near Broadway (G30S) triggered a +22s hold estimate, but train had already cleared the block between 10s polls.
Applied Fix: Increase beacon staleness threshold from 75s → 95s on non-tunnel stops and expand safety guard from -6s → -14s.
Official Miss Caught by Safe Guard Court Sq (N) · 3m 15s before arrival (2 stops away) (Gen 5 (Current))
Official: +29s · Safe: -6s
T1 Term: 0s · T2 Beacon: 0s · T3 Drift: -9s · T4 Seg: -18s · Guard: -14s
Root Cause: Official MTA clock overestimated run-time from Clinton–Washington by +29s (would have missed train). Challenger caught it with 6s to spare.
Proposed Next Update: Candidate Review: When stopsAway == 2 and Kalman drift < -5s/min (accelerating train), widen safety guard from -14s → -17s.
Tight Safe Margin (Near-Miss) Court Sq (N) · 3m 30s before arrival (2 stops away) (Gen 5 (Current))
Official: -18s · Safe: -4s
T1 Term: 0s · T2 Beacon: 0s · T3 Drift: 0s · T4 Seg: +14s · Guard: -14s
Root Cause: Off-peak train skipped normal 15s dwell at Classon Av; Challenger arrived 4s early (safe, but tightest margin in recent window).
Proposed Next Update: Candidate Review: Lower Classon Av (G34N) minimum empirical run-time to G33N from 95s → 88s during off-peak hours.

Persistent Route Database (Firebase Firestore)

Provisioned on Gtrained Cloud DB · Stores /station_calibrations/{stopId}, /backtest_records, and /miss_audits.

Firestore Connected
Bedford–Nostrand (G33) Gen 5
Safe MAE: ±18.0s vs Official: ±53.6s · Guard: -12s
20 verified trips · 100% safe catch rate
Navy Yard & E 34th St (AS_BNY_F34) Gen 5
Safe MAE: ±15.5s vs Official: ±55.3s · Guard: -15s
13 verified trips · 100% safe catch rate