Finding the middle station between two stations (in terms of time)

Unified API
1

Hi!

I want to find the middle station (in terms of time) between two stations, I’m currently trying to use the Journey API to get the distance between two stations as a first step but I’m having trouble with that too.

Could anyone point me in the right direction? Is this available in the API? If not, how could I work it out?

Thanks

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No idea how but just out of interest - what’s the purpose? Apart from helping to answer the question “Are we nearly there?”!

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I can think of two approaches:

Using /Line/Route/Sequence, you could take the latitude/longitude for the two stops, work out the mid-point between them and then iterate through the stops in between to see which one is nearest to that point. It’s not exact as it assumes straight-line travel and a constant speed, but should give a reasonable approximation.

Alternatively you could look at /Line/Timetable and use stopInterval times to work out the nearest to a mid-journey point.

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Welcome @russjohnhop

If you stuff the data from the route into a directed graph, the computation of time is a computationally simple matter.

Just use a sample timetable to work out the timings, or see the WTTs if you don’t mind doing them by hand (for a demo). Working Timetables (WTT) - Transport for London

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Your question is easily answered by web UI and eyeball:

  • Select your start stop
  • Select route and direction
  • View route timetable
  • Select a time period to get a list of journey times in minutes
  • Note journey time to your end stop
  • Your answer is the stop with a journey time of about half.

I used bus stops as an example as I am familiar with it but tube stations are much the same.

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If there is an API call to generate that listing one of the experts on here should be able to tell you what it is.

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@misar @russjohnhop

The API is APIs: Details - Transport for London - API

so the above is found in the API as https://api.tfl.gov.uk/Line/northern/Timetable/940GZZLUCND?direction=inbound

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@mjcarchive I’m putting together an app that helps set a meeting location in-between users, then does a bit more on top of that.

@nickp thanks! I’ll look into this

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@misar thank you, this helps!

@briantist amazing thanks! This looks to be it.

Thanks everyone - this gives me a few options.

1 Like
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@russjohnhop
Thanks for the reply. For me it would usually be a matter of what we want to do after meeting but I suppose it would minimise time if exchanging presents, or other unspecified merchandise!