Driving speeds too fast on single lane roads (highway = primary, lanes = 1). ORS says 12 mins; Google/TomTom/HERE say 20 mins

[johntdata]

Is there an existing issue for this?

• I have searched the existing issues

Problem description

I noticed that ORS produces unrealistically quick drivetimes for highways where lanes = 1. Here is an example, along a section of picturesque but winding single track road in the Highlands of Scotland

https://maps.openrouteservice.org/#/directions/-5.303352136110836,57.604555011028495/-5.50109239525144,57.54281578965259/data/55,130,32,198,15,97,4,224,38,9,96,59,2,24,5,192,166,6,113,0,184,64,90,1,88,3,160,25,128,6,83,76,32,38,1,25,72,13,142,187,200,3,137,128,105,8,29,152,199,200,1,100,34,60,139,114,52,218,8,9,200,64,55,17,98,132,199,150,147,84,172,154,132,234,12,29,207,161,65,146,234,243,109,49,173,66,210,66,113,1,0,3,170,120,17,19,97,202,0,23,148,0,182,185,74,223,182,128,128,3,55,128,1,183,69,193,5,134,135,128,3,114,64,7,55,195,6,70,129,177,4,15,70,15,70,135,68,67,4,139,195,204,134,246,247,205,135,69,129,0,5,241,170,0

ORS estimates this 15.8km route can be driven (default car profile) in 11m40s, which is an average speed of 81kmh. That is absurd and ridiculous when you consider the road is single track with passing places, see photo here.

Start: -5.303352136110836, 57.604555011028495
End: -5.50109239525144, 57.54281578965259

Google maps says 21 mins - https://maps.app.goo.gl/VGT9xsmcMUh3enDU9
TomTom says 20 mins - link here
HERE maps says 20 min - https://share.here.com/r/57.60451217280769,-5.303342237637392,A832/57.5427636927419,-5.501089652734952,A896?a=&m=d&z=17.46&t=normal

ORS at just under 12 mins is plainly wrong. This issue is replicated on all roads in Scotland where lanes = 1. There is a #maxspeed tag of 60mph which is technically the legal limit in the UK, but it would not be possible to drive that fast in real life. So, please can ORS find a way to modify realistic travel speed

Proposed solution

Please revise road speed calculations for single track highways, they are too fast and ORS is hopelessly inaccurate for this use case

Additional context

No response

Forum Topic Link

https://ask.openrouteservice.org/t/how-can-i-edit-openstreetmap-to-make-ors-drivetimes-more-accurate/5430

[TheGreatRefrigerator]

further examples:
https://ask.openrouteservice.org/t/how-can-i-edit-openstreetmap-to-make-ors-drivetimes-more-accurate/5430/5