Missing Bus Countdown Information


Hello All

I’ve noticed in the past few days on my own small app (A smart mirror bus countdown to be precise) and in things like Citymapper, that Bus countdown information is going astray whenever certain buses turn off their engines.

An example route is the 58 whose vehicles seem to turn off their engine at almost every stop or set of red lights, with a instant ‘stop start’ design. Whilst on the buses all would appear fine, the CCTV screens, lights and iBus systems all work fine, yet for the few seconds when an engine is off the buses disappear from the buses next set to arrive at a stop.

This can last for up to 30 seconds at a busy stop and makes it pot luck that you know the bus is coming, as I have noticed a few turning up at my stop without appearing in the feed. Evidently this is not an API / data issue per-se but I wondered why the system doesn’t simply report the last known data until any more is forthcoming, as this would be far more accurate than letting buses fold in and out of existence.

A few other people have alerted me to this issue through apps such as Citymapper and Google Maps. Has anyone else encountered this issue or knows of a potential fix?


Hi @keirjohnharry

This is not one we have noticed ourselves, but thanks for letting us know. We’re always keen to see that the source data that we base our API on is consistent.

I’ll raise the query with my colleagues who deal with Surface Transport, but before I do can you please advise if you are using the Countdown API (countdown.api.tfl.gov.uk) or the Unified API (api.tfl.gov.uk) to get bus predictions?


James Evans
Technology Service Operations


Hi James

Thanks for following up on this so quickly.
Personally I’m using the countdown API though I’ll move to the unified one when I’ve got a free weekend. I would imagine apps such as Google and Citymapper are using the Unified API however.