Index: resources/data/validator/combinations.mapcss
===================================================================
--- resources/data/validator/combinations.mapcss	(revision 16239)
+++ resources/data/validator/combinations.mapcss	(working copy)
@@ -673,4 +673,13 @@
 *[amenity=recycling][collection_times       ][opening_hours][collection_times=~/[a-z]-[A-Z].*[0-9]-[0-9]/] {
   throwWarning: tr("{0} together with {1}. Probably {2} is meant.", "{1.key}", "{0.tag}", "{2.key}");
   group: tr("suspicious tag combination");
-}
\ No newline at end of file
+}
+
+/* #19018 */
+way[highway][crossing][highway =~ /^(motorway|motorway_link|trunk|trunk_link|primary|primary_link|secondary|secondary_link|tertiary|tertiary_link|unclassified|residential|service|living_street)$/] {
+  throwWarning: tr("{0} together with {1}. Should be used on a minor highway type or a node", "{1.key}", "{0.tag}");
+  group: tr("suspicious tag combination");
+  fixRemove: "crossing";
+  assertMatch: "way highway=trunk crossing=unmarked";
+  assertNoMatch: "way highway=construction construction=footway crossing=unmarked";
+}