I’m currently mapping a number of alleys and backstreets in Cardiff, Wales. These are narrow and only allow one vehicle at a time, but are used mainly as pedestrian shortcuts (even though there’s no pavement). Should I tag these with “foot = yes” because service roads don’t imply a footway (or do they?). Or should I not tag anything to do with pedestrians at all, since these roads don’t have pavements?
You can see something similar on Google Maps here:
highway=service would seem to imply foot=yes. Presumably you’re allowed to walk (against traffic) on any street without pavement (US: sidewalk); this would be a special case.
There are a lot of private or permissive service roads around, so I’m not sure what highway=service implies about access. Maybe better to specify explicitly if you know.
If the public have a right to drive along it as well as walk / cycle along it (ie its a public road), then you can tag it as access=yes, which implies foot=yes etc.
In your case, you could use highway=service (+service=alley)+surface=unpaved or highway=track+tracktype=grade1 (where surface is implied, see the wiki)