the primary road (yellow one) appear to be beneath the residential road (white one)
Expected aspect:
the primary road should appear above the residential road.
See image:
Question 1: What should be done in similar cases, what steps should be completed to put primary (important) roads above secondary roads?
Case 2
In some on small intersections are disposed some plastic jersey barrier (white and red) to form a roundabout. Similar with what is in this image:
but much smaller, only from 4 or 5 plastic barriers.
Later edit: please see the image posted on my second post bellow, which is more appropriate for this second case
for case 1, the “primary” is actually mapped as “primary_link”. This might explain why carto-css (the default map on osm.org) puts it below the residential road. Please do not change the road classification just to show it over the residential roads. You can change it, if it is really a primary road and not a primary link road
case 2: A real roundabout is not mapped as a node, but as a “circle”. if it is mapped as a circle, navigation software will say things like “leave the roundabout at the second exit”. In the example you give, I think it is a real roundabout and not a mini-roundabout, due to the jersey barriers. One cannot drive over the center of the roundabout.
Firstly, whether or not it is “on top” is a decision for the person designing the renderer, so there is no absolute right or wrong.
The problem here is that you have a road joining a primary link road, which the renderer does not expect. I’d need to check the definitions, but I suspect this road is not a primary link road, but, if it is, you may have to accept this in the default Mapnik layer. None of the others show this effect.
I would question a one way road joining angled against the flow of traffic!
For question 2, the renderer may have been confused by the inappropriate use of a “lines” tag. However, it is not clear, from the photograph, whether this is really a roundabout, or actually a traffic circle.
Again you should concentrate on a correct description and not change things to make routers work as expected. If they get it wrong, the fix should be applied to them.
Actually, as this is more than a mini roundabout it should have been mapped as a circle, not a point.
The posted image and the intersection from OSM are the same, the image view is from street Cardinalul Iuliu Hossu, on the right is street Vasile Alecsandri.
Not every map treats e.g. primary and primary_link differently; the ones that don’t won’t show the issue here. OSM’s “standard” map has made a design choice to render links below normal roads.