Journey Planner oddity

This result from a search just made for Southgate to Tottenham Hale Station.

The odd thing here is not the choice of bus routes (this part of the Piccadilly Line is closed today) but the advice to get off the 41 at Seven Sisters and walk. Where does the 41 then go? Along Broad Lane and right past Tottenham Hale Station!

Looking at current ETAs on LVF.io for buses on the 41 between Seven Sisters station and Tottenham Hale shows 4-5 minutes, could it be that at this particular time the journey time exceeded the walking time?

I’ve just run what I guess is the same journey (Southgate Station to Tottenham Hale (station)) through Journey Planner for next Saturday around 09:00 and it gave me the same albeit two minutes later…

Looking at the timetable on LondonBusRoutes.net shows the 09:26 departure from Archway as arriving at Seven Sisters Station / West Green Road at 09:48 and reaching Tottenham Hale Station at 09:54. Upton 09:24 they’re timetabled for five minutes between the two but between 09:30 and 11:19 it goes up to six and after that increases again.

Question for @jamesevans and team, I know it was mentioned that Journey Planner now uses live running info. for journey planning that involves the tube, does it do so for buses too?

Simon

@sjcooper @jamesevans
It did the same when I originally put in a journey request an hour and a half earlier, so it should not have reflected any later-in-the-day disruption.

I know I can request a “minimal walking” option but if walking would be quicker it is surely so marginal that getting off the bus at Seven Sisters would be close to lunacy, even when the temperature is not 33 degrees! It would also say something about how slow some bus services are. Just getting across the Seven Sisters junction might account for half the running time; I suppose a pedestrian can dodge that via the subway.

Is walking time calculated from distance alone or does it take into account the time it takes to navigate busy junction like Seven Sisters and Tottenham Hale itself?

I can’t report on actual journey times as I didn’t make the journey. It’s too darn hot,…

Hi, Journey Planner uses live data for the following modes:

  • Bus
  • London Underground
  • Elizabeth line
  • London Overground
  • National Rail

I’m investigating this journey, but just to answer this specific question:

The walking time is calculated from the distance, using the road network rather than a ‘crow flies’ distance. The path taken can be seen by pressing the ‘Map view’ button. By default, it assumes a walking speed of four kilometres per hour.

@LeonByford
Thanks for reply. In my experience walking in central London takes twice as long as walking the same distance in quiet(ish) suburban Southgate (something which residents are “enjoying” in the heat with the 125 diverted again with no replacement!). Unless you are walking along the river side of he Embankment, of course. I don’t know how you could possibly take into account the typical delay factors at every point on every route. I suppose a crude central/inner/outer London differential walking speed is possible but not necessarily desirable. Advising a change of mode for a saving of a minute, if indeed that is what is happening by design or through glitch, doesn’t make much sense to me.

Hi again,

I planned a journey for next Monday evening:

I then re-planned the journey, but instead going via the Tottenham Hale Bus Station stop:

In this way we can see the difference in the two journeys. Getting off at the later stop adds an extra five minutes to the bus journey (which is not completely made up for by the shorter walking leg).

Because Journey Planner prioritises the fastest journeys it returns the 15 minute journey rather than the 19 minute journey.

That’s how the system works, anyhow, but I do realise the journey provided does nonetheless seem a bit odd. We’ll take this away to discuss and see whether there’s anything we should/can adjust.

Thank you for your feedback, as always. :slight_smile:

But there are presumably obstacles other than the x-y plane distance:

  • if a set of traffic lights operates on a 2 minute cycle, it could add up to 2 minutes to the walking distance
  • an underpass (whether slope or staircase) is likely to add at least 50% more to the time to walk the same distance on flat ground, so the underpass should probably be calculated at 2kph rather than 4. It also needs to be based on the actual path taken by the underpass, which will probably be more than the distance between entrance and exit
  • a road without a proper crossing might take a considerable time to cross
  • crossing a road with a central barrier wouldn’t even be possible. Does the current walk time ensure that the chosen route is safe at all times of day?

Yes, I understand that. Journey Planner currently does not have access to that kind of data. However, we are working on migrating to a new GIS data source. I can’t promise anything, but this may pave the way for being able to account for the kinds of factors you outline – it’s certainly something we would like to do.

Seems to me there are two separate issues here.

The first is whether.it is possible to take account of the actual physical conditions affecting a walk. I can see that this is both complex and resource-intensive.

The second is whether it actually makes sense to promote a journey with an extra stage because it gives a very small time saving, even if the time saving is genuine. I can specify minimum number of changes but that could mess up other requests. The option I would like is “ignore marginal benefits resulting from extra changes” but saying that, specifying it to the user unambiguously and deciding the criteria are something else.

I am also well aware that changes can have unintended consequences elsewhere!

I feel the choices we presently have need to be made a bit more granular.

For example, we can only choose “fastest journey” or “least changes” but in practice there ought to be a happy medium where walk time and changes have relative weighting that will sometimes override the journey choice.

There also ought to be a weighting for journey comfort (noise level and crowding) so that journeys from Liverpool Street to Tottenham Court Road are more likely to be routed via Elizabeth Line than Central.

And a weighting for reliability, so that journey legs by tube might be prioritised over buses in heavy traffic areas.

And here’s one that puzzled me for a long time.

  • A journey leg between Gtr Anglia Tottenham Hale and Overground Blackhorse Road frequently tells me to take a bus between the two stations.
  • Very surprising, considering that there’s a Victoria Line tube running every 90 seconds between the two stations, which is just a single stop and obviously would normally get there quicker than the bus
  • Examining it more closely, I came to the conclusion that because the overground only runs once every 12 minutes, it doesn’t matter if the bus takes even 8 minutes longer because it just means you wait longer at BH Road.
  • Except that it doesn’t :slight_smile: I tried it via Victoria Line and on three occasions out of four, I was delivered to BH Road in time for the previous overground train. So, taking the Vic Line for that leg actually cut 12 minutes off the overall journey time.

But the real limitations of journey planner are:

  • it only allows a single VIA point and doesn’t have a not VIA capability
  • I can only turn off tubes in their entirety, not individually (like any tube except Central and Victoria)
  • consequently, I can’t plan a journey that specifies "via Liverpool Street and Tottenham Court road but not using Central Line.

Sometimes it’s OK to leave home 10 minutes earlier to choose a more comfortable route, but it would greatly help to be able to plan it in ONE journey instead of having to break it down into three separate journeys and then try to add up the pieces.