API v3 vs station signage clocks

[Konos]

Hello,

Recently I converted my app to the API v3.

I started getting emails from users that the times visible on station signage clocks don't match times visible in my app.

I started testing this on Green Line at Kenmore-Outbound and I also noticed differences.

This is what I observed:

If train is very close to the station, both (station signage and app) show very similar or the same arrival time predictions.

If train is more than 2-3 minutes away from station, then you can start seeing the difference.

The bigger the distance from station, the more the difference in arrival time predictions between the app and station countdown clock.

What is the reason for this? Are the station signage clocks using different predictions than API v3?

It used to be the same, at lest few months ago when I was testing (at that time my app was using api v2).

Andrzej

[Andrew Ferreira]

I have occasionally seen this discrepancy myself as I ride the T.

[Stefan Wuensch]

I believe the station signs are still using the v2 data, or whatever the MBTA-internal equivalent is.

The press release that just came out yesterday says:
"This lower-latency data is currently available on the website and through the MBTA's v3 API. Over the course of the year, feeds for applications served by the v2 API, in-station signage, and delay messages will be updated."

<https://mbta.com/news/2018-04-20/mbta-improves-accuracy-real-time-information-subway>

That hints that the station signs are on something that is not the most current data feed.

[Developer at MBTA]

Thanks Stefan. You are correct - signs in stations are using data from an older system, which is the system that fed the v2 API data.

We are working to get the infrastructure in place that will put the new API v3 data on the subway countdown signs.