Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/Highways.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/Highways.java	(revision 13347)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/Highways.java	(revision 13348)
@@ -57,5 +57,6 @@
 
     private static final Set<String> KNOWN_SOURCE_MAXSPEED_CONTEXTS = new HashSet<>(Arrays.asList(
-            "urban", "rural", "zone", "zone30", "zone:30", "nsl_single", "nsl_dual", "motorway", "trunk", "living_street", "bicycle_road"));
+            "urban", "rural", "zone", "zone20", "zone:20", "zone30", "zone:30",
+            "nsl_single", "nsl_dual", "motorway", "trunk", "living_street", "bicycle_road"));
 
     private static final Set<String> ISO_COUNTRIES = new HashSet<>(Arrays.asList(Locale.getISOCountries()));