5 minute difference in reported times

[Underway]

We've received a report that between 10/16-10/20 There is a difference of up to 5 minutes reported train arrival times and actual train arrival between 4am and 4:42am.

Reporting this since I know the MTA likes a 2 minute maximum error delta.

Daniel R, Underway

https://underway.nyc

https://underway.nyc/download

[Ben Deutsch // MTA Customer Experience]

Hi there -- do you have any more details about this, including the affected train line(s), station location(s), and direction of travel?

[Underway]

I've asked, I'll report a response as soon as I hear it

[Underway]

This was on the Astoria-bound N line at the Avenue U station.

[Sunny]

Hi,

The root cause of this was an underlying schedule change intended to add additional running time along the N in Brooklyn to account for slower speeds caused by fallen leaves. Due to limitations of our systems, the added time had to be inserted at a specific point, in this case 86 St, which results in trains arriving at some down-line stations earlier than their "scheduled" times resulting in this discrepancy. It would also apply to the countdown clocks at the station, not just the GTFS-RT feed.

The additional running time will be removed in mid-December.

We apologize for the inconvenience.

[Underway]

Thanks Sunny, added running time makes sense given the circumstances. 

I'm curious, couldn't the real-time feed reflect the new expected departure time? What can I do to show New Yorkers accurate departure times? 

In the mean time, I've forwarded your response along. And I have two more reports from the same user. I know the MTA strives for a maximum discrepancy of 2 minutes.

1. The Astoria bound N train at departed 4:16 AM on 10/30/2023 from Avenue U. GTFS-RT stated there was departure from Avenue U at 4:22 AM

2. There is a 4 minute discrepancy in the Astoria-bound N train from the Avenue U station on 10/31/2023. The GTFS-RT time departure was 4:22 AM. The actual time departure from the Avenue U station was 4:18 AM