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<p>This one won't return a subway route because I haven't configured
it for that. I don't have subway trains in the dataset I'm working
with for Toronto. But it would be pretty easy to make a subway
only profile, or to add subways into this one if you want to do
all transit modes in one profile. Take a look at this page for
documentation on how profiles work:
<a class="moz-txt-link-freetext" href="https://github.com/Project-OSRM/osrm-backend/blob/master/docs/profiles.md">https://github.com/Project-OSRM/osrm-backend/blob/master/docs/profiles.md</a></p>
<p>If you want to understand how map matching in OSRM works
generally, I think this paper is a good place to start:
<a class="moz-txt-link-freetext" href="https://www.microsoft.com/en-us/research/wp-content/uploads/2016/12/map-matching-ACM-GIS-camera-ready.pdf">https://www.microsoft.com/en-us/research/wp-content/uploads/2016/12/map-matching-ACM-GIS-camera-ready.pdf</a><br>
<br>
When you change the profile, you're essentially configuring the
street/rail/whatever network that your GPS trace will match
against. Montreal definitely has subways in OSM; you can see them
in the main map at openstreetmap.org.</p>
<p>Best,<br>
</p>
<div class="moz-signature">Nate Wessel<br>
<span style="font-size:10px;color:#777">Jack of all trades, Master
of Geography, PhD Candidate in Urban Planning <br>
<a href="http://sausy.ca">SAUSy Lab</a>, Sid Smith Hall,
University of Toronto</span>
<br>
<br>
</div>
<div class="moz-cite-prefix">On 04/26/2018 10:52 AM, Patrick Agin
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CADY-QyEDZFa=Qm3Da_GjbR+gjS8DevEf=eO6iR_=QAa0uDkBZg@mail.gmail.com">
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<div dir="ltr">Hi Nate and thank you very much for your help. I
have a very basic question about your ttc profile (sorry if it's
too silly). When you match a GPS dataset against this profile
instance, will it return a subway route for example? If yes, why
this subway route would be declared much plausible by osrm than
the street route? Only because of the ttc profile? I realize
that I don't understand very well the involved mechanisms behind
osrm and profiles, if you can shed some light on this, I would
greatly appreciate. Another question: I suppose that the subway
data has to be included in the osm data of my city (Montreal) in
order to get subway routes from match . How can I know if it's
there or not in my osm data?
<div>Thank you again Nate,</div>
<div>Patrick</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">2018-04-26 9:36 GMT-04:00 Nate Wessel <span
dir="ltr"><<a href="mailto:nate.wessel@mail.utoronto.ca"
target="_blank" moz-do-not-send="true">nate.wessel@mail.utoronto.ca</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p>I've had some success with transit matching by simply
modifying the car profile to allow routing on streetcar
tracks, allowing access for buses and public service
vehicles, etc. Here's a profile I'm using for transit
now:<br>
</p>
<p><a class="m_6743982928765403953moz-txt-link-freetext"
href="https://github.com/SAUSy-Lab/retro-gtfs/blob/master/etc/ttc.lua#L347"
target="_blank" moz-do-not-send="true">https://github.com/SAUSy-Lab/<wbr>retro-gtfs/blob/master/etc/<wbr>ttc.lua#L347</a></p>
<p>I had also tried to develop a more transit specific
profile from the ground up. My thought was that known
transit routes (provided in the OSM data) would be
preferred by modifying their edge weights. This however
ran into an issue with the matching service which hasn't
been resolved yet; edge weights simply aren't used in
match results. <a
class="m_6743982928765403953moz-txt-link-freetext"
href="https://github.com/Project-OSRM/osrm-backend/issues/4785"
target="_blank" moz-do-not-send="true">https://github.com/Project-<wbr>OSRM/osrm-backend/issues/4785</a></p>
<p> If anyone has a suggestion for the question about
multimodal paths, I would be very keen to hear it,
however I suspect this is still an open topic of
research with no definite best practices. <br>
</p>
<p>Best,<br>
</p>
<div class="m_6743982928765403953moz-signature">Nate
Wessel<br>
<span style="font-size:10px;color:#777">Jack of all
trades, Master of Geography, PhD Candidate in Urban
Planning <br>
<a href="http://sausy.ca" target="_blank"
moz-do-not-send="true">SAUSy Lab</a>, Sid Smith
Hall, University of Toronto</span> <br>
<br>
</div>
<div>
<div class="h5">
<div class="m_6743982928765403953moz-cite-prefix">On
04/26/2018 09:01 AM, Patrick Agin wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div class="h5">
<div dir="ltr">
<p>Dear all,</p>
<p>I'm a newbie to routing engines and my first
attempts are with OSRM. Specifically I want to
use the<span
class="m_6743982928765403953gmail-Apple-converted-space"> </span><em
style="font-family:inherit;font-variant-caps:inherit;font-weight:inherit;margin:0px;padding:0px;border:0px;font-stretch:inherit;line-height:inherit;vertical-align:baseline;box-sizing:inherit">match </em>service.
Questions I have is :<span
class="m_6743982928765403953gmail-Apple-converted-space"> </span><br>
</p>
<p>1) is it possible with match service to specify
public transport (e.g. subway) as the mode of
transportation? I see only profiles for car,
bike and foot. If not, is there a solution? I'm
pretty sure it it possible but how? I saw in
some profiles the public_transport parameter but
I don't know how to use it.</p>
<p>2) is it possible for match to return a
multi-modal path given the timestamps of each
coordinate? For example, return a sub-path that
is the most plausible for pedestrian (chosen
because of the low speed inferred from
timestamps) followed by another subpath that is
the most plausible for car (because of a higher
speed)? Or is the only solution to pre-process
the data to infer by myself the mode of
transportation and make subsequent calls to the
corresponding profile instance?</p>
<p>Thanks a lot,</p>
<p>Patrick</p>
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