Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/ConditionalKeys.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/ConditionalKeys.java	(revision 15742)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/ConditionalKeys.java	(revision 15743)
@@ -30,5 +30,5 @@
     private static final Set<String> RESTRICTION_TYPES = new HashSet<>(Arrays.asList("oneway", "toll", "noexit", "maxspeed", "minspeed",
             "maxstay", "maxweight", "maxaxleload", "maxheight", "maxwidth", "maxlength", "overtaking", "maxgcweight", "maxgcweightrating",
-            "fee", "restriction", "interval"));
+            "fee", "restriction", "interval", "duration"));
     private static final Set<String> RESTRICTION_VALUES = new HashSet<>(Arrays.asList("yes", "official", "designated", "destination",
             "delivery", "customers", "permissive", "private", "agricultural", "forestry", "no"));