# Isochrone driving polygons not following road network as range increases

**URL:** <https://ask.openrouteservice.org/t/isochrone-driving-polygons-not-following-road-network-as-range-increases/5193>\
**Category:** isochrones\
**Created:** [August 30, 2023, 3:18pm UTC](https://ask.openrouteservice.org/t/isochrone-driving-polygons-not-following-road-network-as-range-increases/5193 "2023-08-30T15:18:06Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![amandus](https://ask.openrouteservice.org/user_avatar/ask.openrouteservice.org/amandus/32/669_2.png) [@amandus](https://ask.openrouteservice.org/u/amandus)\
**Post date:** [September 4, 2023, 12:59pm UTC](https://ask.openrouteservice.org/t/isochrone-driving-polygons-not-following-road-network-as-range-increases/5193/2 "2023-09-04T12:59:22Z")

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Hi @johntdata,

first of all: Amazing example!  
we should use this approach when testing or investigating isochrones…

Just off the top of my head: This might probably be this issue [Different isochrones when specifying multiple travel time ranges vs just one range](https://ask.openrouteservice.org/t/different-isochrones-when-specifying-multiple-travel-time-ranges-vs-just-one-range/3944) (this links to several threads/issues that explain the problem further)

In that case, there is probably no other fix than editing the algorithm code itself.

But it might also be the switch to a different isochrone algorithm for greater ranges.

Could you provide the docker image/ or git commit hash and the configuration of the ors instance you are running and probably the code/commands to reproduce the used osm file from the scotland.pbf?

Best regards

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_[View the full topic](https://ask.openrouteservice.org/t/isochrone-driving-polygons-not-following-road-network-as-range-increases/5193)._