# ORS drive time isochrones

**URL:** https://ask.openrouteservice.org/t/ors-drive-time-isochrones/4632
**Category:** Maps Website
**Created:** [March 8, 2023, 3:24pm UTC](https://ask.openrouteservice.org/t/ors-drive-time-isochrones/4632 "2023-03-08T15:24:21Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Goldian](https://ask.openrouteservice.org/user_avatar/ask.openrouteservice.org/goldian/32/2012_2.png) [@Goldian](https://ask.openrouteservice.org/u/Goldian)
#### Post date: [March 8, 2023, 3:24pm UTC](https://ask.openrouteservice.org/t/ors-drive-time-isochrones/4632/1 "2023-03-08T15:24:22Z")

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Just had a quick question - I did some few isochrones with population (driving) on the online tool, but have now moved per to qgis

I am seeing much smaller populations from Qgis for UK 12 min drive time isochrones - could you help me with why that may be ?

It is clear that Qgis uses some form of average peak or non peak actual speeds a la google maps)

Would I be right that ORS are using just the relevant road speed limits as opposed to actual traffic speeds ?

I guess for walking and cycling this wont be different but of course will be for driving

Is there any way of amending driving assumptions if the above is correct ?

Many thanks

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### Author: ![jschnell](https://ask.openrouteservice.org/user_avatar/ask.openrouteservice.org/jschnell/32/971_2.png) [@jschnell](https://ask.openrouteservice.org/u/jschnell)
#### Post date: [March 9, 2023, 3:18pm UTC](https://ask.openrouteservice.org/t/ors-drive-time-isochrones/4632/2 "2023-03-09T15:18:19Z")

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Hey,

when you say you “moved per to qgis”, I assume you were using [maps.openrouteservice.org](http://maps.openrouteservice.org) before and are now using the QGIS plugin ORS Tools.  
If not, please correct me.

In that case, if you send the same isochrone request (i.e. same starting point and same range), you should get the same isochrone and thus the same population.  
If that is not the case, please provide both requests - via screenshots or via the `Log Messages` panel (QGIS) and the Dev Tools Network tab (maps client).

What do you mean by

> [@Goldian](#):
>
> It is clear that Qgis uses some form of average peak or non peak actual speeds a la google maps

Have a look [here](https://ask.openrouteservice.org/t/calculation-of-min-range/4569/2) for a short comment on road speeds used by openrouteservice.  
There should be more info on this topic in the forum.

Best regards.