I am trying to represent isochrones from a points layer using ORS Tools in QGIS 3.8.3-Zanzibar.
Does anyone know why there are some gaps in the resulting polygons, even though the road, according to the OpenStreetMap base layer underneath, is continuous? (OpenRouteService works with OpenStreetMap, so the same network should be used to build the isochrones, right?)
I am especially concerned about the highways and main roads.
Here are some examples:
The parameters I used in the ORS Tool were (after obtaining and input the API key):
Isochrones from layer option
Provider = openrouteservice
Input point layer= a layer with 12 points (not very complicated as to see the outputs easily)
Travel mode= driving-car
Dimension = time
Ranges in minutes = 15,30,45,60
If, as the last image shows, the polygons are created following vertices and not just the polylines of the road, how could I densify (as suggested in an answer) the network ORS uses?