CTA Train Tracker Map - Help & Notes

The CTA Train Tracker sm Map shows you where in-service trains are across the ‘L’ system. This new feature is an extension of the main, CTA Train Tracker Estimated Arrivals service.


How do I use this?

Select one or more routes (on the left) to see the normal path of trains and all trains on that route. The route you've selected will be highlighted on the map and icons for any trains flagged as being in service on that route will be shown.

The map shows only trains that are in service (i.e., have left the terminal and are on the move). The info you see is a visual representation of the same data that we use to make estimations for when trains will arrive at stations.

You can click on a train or stop for estimated arrivals.


I really just need to know when to be on the platform. Why provide a map?

Because it’s one of the most-requested features. We always anticipated that it would be, so it’s been on our radar. Quality of arrival info has always been our highest priority so that had to come first, but we’ve regularly had this come through our feedback form as a feature request—so here it is!

While arrival info is probably most useful for quickly making a decision, we find that we, like many of you, also like to see things on a map as added confirmation that service is imminent.


How come the route colors don't look right on the map sometimes?

We built the map using simple, real-world route lines representing precisely where our tracks go drawn on a real map, so there are places where colors will overlap each other and the appearance won't be precisely the same as our printed maps, which offset lines for clarity as a navigation tool. This service isn't a navigation tool so much as it is information about where trains are in relation to the physical CTA 'L' system.


How come sometimes I don’t see anything on the Yellow Line?

Because this service is only able to show trains that have left their terminals, and because the Yellow Line is a short route often served by just two trains going back and forth, the Yellow Line may appear to have no service running when, in reality, both trains just happen to simultaneously be at opposite terminals, turning back between trips.

When trains are in operation between terminals, they do appear on the Train Tracker map.


Why do I see a train away from its normal route?

In some circumstances, a train might change routes or be sent down another route’s track to supplement service where more capacity is needed or to be rerouted around a blockage or heavily congested area as a part of procedures we implement to restore service after an incident.

The CTA Train Tracker Map will still show trains that have left their route in many circumstances, though those which have gone into service as a different type of train may not always be accurately represented. We’re aware that there can be some quirks when trains change routes, and we’ll be refining how the system handles and presents this info, as we develop this new service further.


Is there a mobile version?

Sorry, but no. This Web-based map feature works best in modern browsers on desktop computers, though we’ve tested it on a few tablets and even smartphones and find it to work pretty great, there, too.

While we don’t make smartphone apps directly, we do actively support the independent development community by releasing free, public data to power app makers’ projects, which are what you find when you look for transit apps in your phone's app store or marketplace.

The developer community is really enthusiastic about creating great transit apps (there are many!) and we’re confident that, once we release location data for transit apps, developers will do all sorts of great things with it.


Is there an API for developers to use?

We’re working on it. We’ll soon be releasing an API into train location data.

We understand that this is an exciting new feature lots of you have been waiting for, but we just need a little time to finish the development on the API bits. We're sorry we don't have this yet, but we appreciate your patience while we put together something that'll be stable and supported.