Index: resources/data/validator/highway.mapcss
===================================================================
--- resources/data/validator/highway.mapcss	(revision 17884)
+++ resources/data/validator/highway.mapcss	(working copy)
@@ -8,6 +8,14 @@
   set minor_road;
 }
 
+/* #9819 */
+way[layer][!bridge][!tunnel] {
+    throwError: tr("{0} needs additional tags -> either {1} or {2}.", "{0.tag}", "bridge=*", "tunnel=*");
+    assertMatch:   "way layer=1";
+    assertNoMatch: "way layer=1 bridge=yes";
+    assertNoMatch: "way layer=-1 tunnel=yes";
+}
+
 /* r3669, #9384, #20117 */
 way[highway][name =~ /(?i).* (Ave|Blvd|Bnd|Br|Brg|Cct|Cir|Cl|Cr|Crct|Cres|Crt|Ct|Cv|Dr|Drv|Esp|Espl|Hwy|Ln|Mw|Mwy|Pky|Pkwy|Pl|Rd|Qy|Qys|Sq|St|Str|Ter|Tce|Tr|Trl|Vw|Wy|Xing)[.]?$/] {
   throwWarning: tr("abbreviated street name");