I struggle telling apart asphalt and concrete

[marie-bnl]

I read on the Internet that concrete is very rigid and light gray while asphalt is way darker and more flexible, however the roads in my city are all tagged surface=asphalt although they are as light as concrete and feel very rigid.

I think brand new asphalt would be rather easy to tell apart, but old asphalt / concrete look indistinguishable to me.

The pictures in the app aren't very useful either because it's hard to see what is relevant, the color is not helpful, the surface looks the same, there are some cracks and seams but I'm not sure these can be relied upon.

Maybe this is a quest I should leave to car drivers? I'm a pedestrian, maybe drivers do feel the difference.

[matkoniecz]

Can you share a photo? This may enable others to help.

(also, you can disable quest in settings if you want)

[marie-bnl]

I am not trying to answer this for a particular road, I'd like general advice on telling them apart and I think plenty of users can find examples of old asphalt, but I can share a photo tomorrow if that helps.

I also have disabled the quest but I am probably not the only person struggling with that so I'd like this discussion to serve as a source of information for others who do.

Moreover I'd like to think about edits that could be made to StreetComplete, for example editing the pictures, adding textual tips... I feel like no quest should assume you're a road engineer.

[ERYpTION]

Instead of disabling the quest have you considered simply answering 'Paved (generic)' when in doubt? I would think this is still of value for routing engines.

[marie-bnl]

Doing this is misleading, it would suggest: "I did the survey and the road is paved but in a material that is not in the list".

The quest would then not appear to other user since the road surface now has value. Additonally the source of my edits is a survey and you should probably trust survey more than any other source. So fixing the road surface would require a user to be interested in this particular road, survey it, edit it in an external editor and not trust that I selected paved because it was the most appropriate choice. It is equivalent to condemning the road surface to be overly generic for virtually ever.

IMO it is better to leave the road surface undefined until a user gets the quest and is able to answer precisely.

[ERYpTION]

You could be right, although it seems highways tagged 'Paved (Generic)' have their own distinctive color (black) in the SC surface layer, which at least for a SC mapper it should make it easy to notice that these could still use a more accurate surface description.

I would be curious to see those road surfaces, that are so difficult to distinguish. I wonder if they are a special kind not used where I live. It is very rare that I have had any difficulty distinguishing asphalt from concrete, in aerial photographs sure, but not up close.