I do not know how to create an Overpass query to find “restriction=no_u_turn”, where the from and to roles refer to the same way. The reason is that I am removing examples that do not exist on the ground in Greece, which were added en masse by the now-suspended user Map-Finder (the same user who flooded the map with guides tagged as a pipeline).
OT\ Know of countless here that are not signed, mapped in kind of an autoreflex on ways coming off roundabouts, often only a painted/chevron separation between the on and off, but most frequently having a solid_line divider following on to which navigators take no cue i.e. are agnostic of the divider markings. I let them be. The divider lining is generally good inserting a dash line divider where driveways are practically directly after the roundabout flare… solid divider lines have short dash sections where driveway/service ways/farm tracks meet road i.e. solid does signify, “only_straight_on”.