Correction Protocol

I’m new to OSM and am starting by trying to correct a few errors around my village. There are a few streets running through the village that are tagged ‘highway=residential’, but I believe they would be better tagged as ‘highway=tertiary’ and ‘abuttal=residential’. Is it ok to just make these changes, or could this upset whoever spent a lot of time and effort setting it to what they believe to be best? Should I be seeking to discuss the changes with the originator of the data first?

If something is incorrect, then it is fine to correct it.
Though if it is a tagging disagreement, then you should check the tagging guidelines first, which may vary by country. And possibly discuss it, ie on this forum or mailing lists, or contact the other mapper.

For the UK, see and
In the UK, the differences between tertiary, unclassified and residential roads are sometimes unclear, as they usually not signposted as such on the ground.
I would suggest something like this:
Tertiary - a busier through route (which is not an A or B road). It may the main street through a village, and the main route to the next village, or the connection to the nearest main road etc.
Unclassified - a more minor road, you would usually only drive along it if specifically going to a house beside it, it may be a dead end.
Residential - a minor road in a residential area, again usually only drive along it to get to a house, probably low speed limit.

So tertiary roads are more important, and usually wider relative to other roads in the area. Often two-lanes, whereas unclassified roads are probably single-track with passing places. Though in more rural areas tertiary roads can be single-track (as well as single-track A and B roads).
So yes, you can get tertiary and unclassified roads in towns/villages, including in residential areas. Note it is usually best to map residential areas as an area tagged landuse=residential. If this is done, you don’t need an abutters tag.

It may be possible to check the council official list of roads, which should specify which are designated as “C-roads” (tertiary) or “U-roads” (unclassified/residential). Though these lists are probably copyright, you should not use it for adding anything to OpenStreetMap, unless you have got specific permission.

Thanks for your help. I am fairly confident that what I am looking at is a tertiary not unclassified road. It is in the UK, it has a white line down the centre and is plenty wide enough for two cars to pass safely while travelling at the national speed limit. It runs from a major B road up to the village and eventually runs into the main street of the village. It is also a bus route. So ‘unclassified’ just doesn’t fit well with me. I just don’t want to upset someone by overriding their hard work.

Thanks for the references. There’s a lot of useful information out there, but it really helps to have relevant stuff pin pointed.