Index: resources/data/validator/highway.mapcss
===================================================================
--- resources/data/validator/highway.mapcss	(revision 17912)
+++ resources/data/validator/highway.mapcss	(working copy)
@@ -163,4 +163,12 @@
   throwWarning: tr("{0} together with {1}", "{0.tag}", "{1.tag}");
   suggestAlternative: "kerb=*";
   group: tr("suspicious tag combination");
+}
+
+/* #20442 Addressing traffic signals on roundabouts */
+node[highway=traffic_signals][traffic_signals=signal] < way[highway][junction=roundabout],
+node[highway][highway=~/^(traffic_signals|stop|give_way)$/][!traffic_signals] < way[highway][junction=roundabout] {
+  throwWarning: tr("{0} without right of way", "{1.tag}");
+  group: tr("suspicious tag combination");
+  suggestAlternative: "junction=circular";
 }
\ No newline at end of file