[OSRM-talk] maxspeed and speeds in car.lua HELP

[Silvia Oviedo]

Thank you for your answer.

I have been changing the speeds in the car.lua profile and routing between
different points with different distances. I have found that, for longer
routes if I reduce all the speeds of the profile, there is a noticeable
difference in the travel times, but it is not the same for shorter
distances. From reading the code, I don't understand this behaviour, can
someone point out possible causes?

Longer Route:
http://localhost:5000/route/v1/driving/-2.130661,52.586363;-1.506500,52.408284?steps=true&alternatives=true&overview=full&geometries=geojson

Medium Route:
http://localhost:5000/route/v1/driving/-1.823924,52.560484;-1.897888,52.481578?steps=true&alternatives=true&overview=full&geometries=geojson

Small Route:
http://localhost:5000/route/v1/driving/-1.823924,52.560484;-1.897888,52.481578?steps=true&alternatives=true&overview=full&geometries=geojson

*Longer Route * *distance (Km)* *time (min)*
at original speed 59.6 60
at 2/3*speed 58.4-60.5 66-73.4
at 1/2*speed 58.4-60.7 71.4-78.8
at 1/3*speed 58.6-58.4 78-79
*Medium Route* *distance (Km)* *time (min)*
at original speed 11.6-12.4 15.6
at 2/3*speed 11.6-12.4 16-19
at 1/2*speed 11.6-12.4 16.3-20
at 1/3*speed 11.6-12.4 17-20
*Small Route* *distance (Km)* *time (min)*
at original speed 0.338-0.387 50.3-64.9
at 2/3*speed 0.338-0.387 50.3-64.9
at 1/2*speed 0.338-0.387 50.3-64.9
at 1/3*speed 0.338-0.387 50.3-64.9


Thank you.

El vie., 23 ago. 2019 a las 1:32, Florian Lohoff (<f at zz.de>) escribió:

> On Fri, Aug 16, 2019 at 02:15:07PM +0200, Silvia Oviedo wrote:
> > Hi everyone,
> >
> > I would like to have your input regarding this:
> >
> > In OSM there is tag: maxspeed. In my case, I find that the majority of
> the
> > primary roads have 30mph ~ 48 kph as a max speed. In the car.lua, I find
> > that the highway speed that has been set primary is 65 kph. Is the speed
> in
> > the OSM tag taken into consideration? I understand that the speed table
> is
> > accessed by WayHandlers.speed() function but I am not sure what's the
> > effect of WayHandlers.maxspeed().
>
> Hi,
> maxspeed, width, oneway, lanes and surface tags are used to determine the
> weight/cost/estimated speed to travel segment - A lanes=1 without
> any oneway will typically assume its typically speed is something like
> halve of the maxspeed. But the whole issue is more complex as lanes
> and maxspeed may carry :forward/:backward suffixes etc.
>
> So the car.lua with the help of lib/maxspeed.lua and others do that
> estimation. If there is no maxspeed osrm has some assumptions for
> road classes.
>
> Flo
> --
> Florian Lohoff                                                 f at zz.de
>         UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away
> _______________________________________________
> OSRM-talk mailing list
> OSRM-talk at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/osrm-talk
>


-- 
Silvia Oviedo Castillo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/osrm-talk/attachments/20190829/e175e73a/attachment.html>