Mapping from Aerial Images

In the past, most users tended to tag roads from the aerial as ‘road’, suggesting that the entry was tentative. It seems that now many roads are asserted as ‘residential’ or whatever even if the user can’t possibly be sure they are real. This works of the image is clear, but many are not.

I recently biked an area where the images were very poor, yet some OSM roads were drawn as if they were real. Many were not. Major roads were missed because it was not possible to see just what they were.

I think it would be better to label anything that is not very clear on the aerial as ‘road’.

A big problem with this is that most people looking at the map will assume that they are right, and users looking for a place that needs work will miss these areas.

For an example from the past

If those “roads” do not exist at all, that’s a much worse problem than a mis-tagged road.
What did you find instead of the mapped roads on the ground there? Overgrown tracks or something else?
In Turkey, I had some problems of distinguishing dry river banks and roads (and some dry rivers were actually used as roads…).

In suburban areas I quite often can’t really tell whether a soi is a public street (highway=residential) or a private driveway (highway=service), regardless of imagery quality. Sometimes I tag these as highway=road, but sometimes I just try to make a best guess, since it doesn’t seem that big of an error. I think my case is quite different from your example though.

If something look “big and important” on an aerial then tag it as such. A paved road with two lanes and markings visible, also some cars on them possibly connecting multiple villages to higher classified roads, then tag it as such. The change of an error here is quite small (not zero. Roads can change routes due to various reasons and aerials can be outdated)

I often use “highway=unclassified” as a safe guess. Most likely those roads are even higher class but I tend not to tag them if not having the local knowledge on the ground.

Keep in mind that a highway=road is not used by routing. They treat the roads as if they do not exist. So especially for larger roads connecting villages you do no good in tagging them as such.

If a road can’t be seen on aerials, for example due to cloud coverage I check alternative sources. Try Bing, Mapbox or even load GPS traces from OSM. In many cases this helps to get the needed details. If this is not sufficient I usually don’t paint the roads.

There are rare cases when I use low-res imagery to complete roads, but these must be the exception as that imagery misses a lot of details and often comes with an offset.