Did you mean, it should be like:
rather than like this?:
From the wiki, divided highways (or what they say double- or multi-carriageway in the UK) should be mapped separately: Tag:highway=trunk
I reckon it applies to every kind of highway, including the service ones.
Perhaps they need to be updated to show that they are in fact double carriageway highways.
Keep in mind, OSM database is used as well in e.g. Project Open Source Routing Machine besides e.g. Garmin. So, I guess, turn restrictions are more important rather than clean looks.