Streetcomplete: Default-speed for zones

[W-T-Developer]

I suggest a one-click option to select 30km/h-zone instead of choosing speed-zone and entering 30 manually.
Of course other countries may have other default zone-limits.

[westnordost]

Fair enough. This however requires research which speed zones are common in the different countries that have them.

This is a list of all countries that do have slow zones: https://github.com/westnordost/StreetComplete/blob/master/res/country_metadata/isSlowZoneKnown.yml

For this to be implemented, we need (another) list where, f.e. a file like commonSlowZoneSpeed.yml in this format:

DE: 30
...

Research could happen via taginfo, f.e. https://taginfo.openstreetmap.org/search?q=zone40#values

A short look reveals that in many countries zone20, zone40 zones are known, but are somewhat less common that zone30. Countries where the zone30 is not the absolute clear winner in terms of usage should not prefill 30 into the text field.

[westnordost]

Are you up for doing that research? Then I am up to implementing it.

[rouelibre1]

Sources to help the with the research :

https://www.eltis.org/in-brief/news/stockholm-declaration-wants-general-30-kmh-speed-limit
https://innovationorigins.com/a-30-kilometers-per-hour-speed-limit-in-all-residential-areas-alone-is-not-enough/
https://www.thelocal.es/20201022/spain-will-lower-speed-limit-in-cities-to-30kmh-to-curb-spike-in-accidents

TL;DR :

• 30 km/h is already the default limit in many major cities across Europe (sometimes not the default but already widespread, and/or set to become the default in a short timeframe).

• Ministers from around the world met to adopt the “Stockholm Declaration” at a conference in February which includes commitment to 30kmh (20mph) speed limits where vulnerable road users and vehicles mix (in urban areas).

• Setting a speed limit of 30 km/h should become “the new normal” in all places where cars, cyclists, and pedestrians frequently interact

[matkoniecz]

Note what we are interested in what is actually signed right now, not in the plans.

[W-T-Developer]

Instead of a configured default value, a button to select my last choice could also be helpful.

[RubenKelevra]

Yeah I think that makes much more sense. In Germany we got 20 and 30 zones, but you basically just want to get to the last value most of the time.

[westnordost]

Ok, fair enough.