
London Bus Stop Distance Analysis - michjedi
https://www.michalpaszkiewicz.co.uk/blog/busdistributions/index.html
======
zimpenfish
Needs a discussion of the methodology of calculation.

The distances I'm getting from the downloaded "bus-sequences.csv" (from TfL's
API site) differ substantially; e.g my 53 has averages of 317m and 357m vs his
201m and 219m.

Additionally, my numbers match up with those of 'superqwert from
[https://news.ycombinator.com/item?id=20029476](https://news.ycombinator.com/item?id=20029476)
for the 389 and 631 routes.

(I measured a bunch of stops of the 78 route with GPS earlier this week. My
calculations correlated closely with the real* distances when the looseness of
GPS from downstairs on a bus is taken into account.)

~~~
superqwert
The numbers on 389 and 631 agree with my post linked above to 3SF... Rerunning
my previous query on 53 gets me:

min: 11.176937891670061

lq: 69.77607205565486

med: 147.79705350080133

avg: 219.3995096050874

uq: 291.84606245281907

max: 1121.239174918762

I wonder where you got your csv data from exactly? I found a csv
([https://tfl.gov.uk/cdn/static/cms/documents/stop-
sequences-e...](https://tfl.gov.uk/cdn/static/cms/documents/stop-sequences-
example.csv)) that is labelled "The example feeds below are not updated and
for demonstration purposes only".

For my query I called the route sequence API directly:

[https://api.tfl.gov.uk/line/53/Route/Sequence/inbound](https://api.tfl.gov.uk/line/53/Route/Sequence/inbound)

~~~
zimpenfish
The CSV is this one - [http://tfl.gov.uk/tfl/syndication/feeds/bus-
sequences.csv?ap...](http://tfl.gov.uk/tfl/syndication/feeds/bus-
sequences.csv?app_id=&app_key=)

I get the same sequence of stops from that API link that the CSV has for route
53, run 2, albeit with northing/easting location instead of lat/long.

(I'm extremely sceptical about the 11m minimum distance too - having done the
entire 53 route a few times, I can't remember any stops that are basically _on
top_ of each other.)

~~~
superqwert
I think I've found the issue with the 11m distance - the 11m distance is:

[-0.126102, 51.502769] to [-0.126018, 51.502714]

What is happening is that the TfL sequence API is starting the bus route
sequence on one side of the road of Parliament Street, before turning it
around at the corner with Whitehall Place. The bus stops on either side of the
road are very close together. Other maps/sequences elsewhere start the
sequence at the end of Parliament Street, meaning the short distance is
avoided.

~~~
zimpenfish
Ah, you're parsing the `lineStrings` blob? I'm looking at the lat/long pairs
in the `stopPointSequences` structure[1] which gives a different set of coords
(in particular, 51.502769, -0.126102 doesn't exist as a stop for the 53.)

[1] `.stopPointSequences | .[0] | .stopPoint | .[] | [.name, .id,
(.lat|tostring), (.lon|tostring)]` in jq parlance

~~~
superqwert
Interesting! I wonder why the Line strings blob differs... Maybe it doesn't
represent bus stops at all, but points at which the route changes for the
purpose of drawing?

~~~
zimpenfish
It does seem to be "the route as you'd show on a map" \- if I plot the two
sets points on GPSVisualizer, it's fairly different.

[https://imgur.com/a/BUSW3C2](https://imgur.com/a/BUSW3C2)

I guess the 389/631 routes are reasonably simple and don't need more "drawing
points" than you'd get from the bus stops anyway?

[edit: added the 389 bus stops and line points to the imgur gallery]

~~~
superqwert
nice!

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snthd
TFL uses so called PTALs to put a number on public transport accessibility.

[https://en.wikipedia.org/wiki/Public_Transport_Accessibility...](https://en.wikipedia.org/wiki/Public_Transport_Accessibility_Level)

On a map - [https://tfl.gov.uk/info-for/urban-planning-and-
construction/...](https://tfl.gov.uk/info-for/urban-planning-and-
construction/planning-with-webcat/webcat?intcmp=25932)

------
mattlondon
I wish we had more "long distance" buses in London.

It takes forever to get anywhere on a bus because it stops so frequently. I'd
be really keen to get buses that dont stop until they get to major places.

E.g. you could have bus routes that only go between stations on different
routes. Take Camden Town to Finsbury Park as an example - no direct rail route
between them, about 2.5 miles apart by road. The 253 stops _sixteen_ times
(according to Google Maps) when going between those stations.

~~~
HenryBemis
To the exact opposite side of that spectrum/opinion; I rarely use buses in
London -underground is more convenient for my routes- but the few times I have
to use a but, it mostly is the Night Bus(es).

It amazed me how it makes one stop almost on every block (statistics seem to
agree on that). Yes it becomes annoying if your route is 5k-10k (or start-to-
end), but I was thinking of all the people that need to use the bus, in the
middle of the night, on areas that may not be very well lit, it is MUCH safer
if they have to 50m-100m than 1km.

It is just a trade-off between speed vs safety/comfort/convenience.

I am also thinking that during the day this makes the life of older people,
people with mobility challenges, parents with prams, shoppers, school children
so much more comfortable.

~~~
inferiorhuman
In San Francisco there are some block with maybe five different bus stops on
them. In general many routes stop every block, or nearly every block. Part of
the reasoning is that there are standards for stop spacing. Off the top of my
head I don't remember the specifics but it's along the lines of x% of the
city's population must have a bus stop within y feet that provides service at
least z hours a day. Stops along a line must be within n feet unless it's on a
grade > j% in which case the distance is some fraction of n.

This all works extremely well in theory but is incredibly resource intensive.
There've been plenty of discussions on how to speed up service by eliminating
some stops — but this is complicated by Muni being a system with a dependency
on transfers and by people having their own favorite pet stop. So what
happens? Muni goes after lightly used lines — like the line that served
Treasure Island. Of course the geniuses at Muni didn't seem to care that you
can't walk/bike to Treasure Island. It's personal or public motorized transit
only (or it was when they first tried to gut the 108).

The night buses in San Francisco are a godsend, and quite unique in the Bay
Area, but not particularly well utilized — partly a visibility issue I'm sure.
The stops are generally about as frequent but the service itself is much less
frequent (once or twice an hour typically — or roughly 1/2 to 1/4 the daytime
service) and there are fewer routes (a few routes run 24x7, there are bus
lines that replace the rail lines stop for stop, and two or three dedicated
"Owl" lines). Aside from the really infrequent schedules, the biggest
challenge is that runs go missing all the fucking time because absolutely none
of the street supervisors even notice when the first run or two doesn't go
out. Of course once you get on a bus, if you're on an owl route… good luck
figuring out where the driver is going to stop.

Meanwhile in London I remember taking the bus from Liverpool St station around
1am ages ago (the 23?). The service seemed reasonably frequent and there were
plenty of stops (same as the daytime as far as I could figure). The big
challenge I had was understanding the driver — I couldn't see very well out
the window. I remember the bus itself seemed fairly crowded — compared to SF
where the night buses really empty out as you get away from downtown / market
st.

The one thing I've seen that I think would benefit SF (and to a lesser extent
London or any area looking to beef up their late night service) was in New
York. If you're on a bus at night the drivers are allowed to let you off
anywhere along the route as long as it appears safe to do so.

------
simplesleeper
related:
[https://news.ycombinator.com/item?id=20029476](https://news.ycombinator.com/item?id=20029476)

------
idlemind
For the TfL API, have a look at
[https://api.tfl.gov.uk/](https://api.tfl.gov.uk/). You can also get GeoJSON
line strings of the bus stops (or other modes of transport!) if you’re
interested.

------
Schmazo
Some people who you might not normally expect to, do concern themselves about
bus routes.

[https://www.sidis.net/TransfersContents.htm](https://www.sidis.net/TransfersContents.htm)

~~~
JadeNB
Does this person have some reputation that others of us could recognise, that
would lead us to expect him not to be interested in bus routes? I found the
site mystifying, but clicking around suggested someone more on the Timecube
than the eminent-public-figure side.

~~~
atdrummond
W.J. Sidis was one of the 20th century's most well known classical polymaths.

------
michjedi
Thanks all for the help - some of you noticed the data was erroneous. It is
all fixed now

