Hmmm, it's a shame it isn't used. I just know that StreetComplete won't prompt for surface details on link ways.  (https://github.com/streetcomplete/StreetComplete/blob/1b4cc774fef0483e4cdccedcbc36b0f5122e0873/app/src/main/java/de/westnordost/streetcomplete/quests/surface/AddFootwayPartSurface.kt#L31)

Obviously we can't use streetview as the direct source due to copyright, but you can see the sign I'm referencing here: 

https://www.google.com/maps/@50.8872408,-1.3720885,3a,49.4y,239.6h,82.96t/data=!3m7!1e1!3m5!1sn0es5nEucGZCbr3SnSR1EQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3Dn0es5nEucGZCbr3SnSR1EQ%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D137.35605%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192