Index: trunk/src/org/openstreetmap/josm/data/validation/tests/ConnectivityRelations.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/validation/tests/ConnectivityRelations.java	(revision 19579)
+++ trunk/src/org/openstreetmap/josm/data/validation/tests/ConnectivityRelations.java	(revision 19580)
@@ -170,4 +170,5 @@
             }
         }
+
         // Lane count from member tags
         for (RelationMember rM : relation.getMembers()) {
@@ -180,5 +181,9 @@
                     long maxLaneCount;
                     if (prim.hasTag("lanes")) {
-                        laneCounts.add(Long.parseLong(prim.get("lanes")));
+                        try {
+                            laneCounts.add(Long.parseLong(prim.get("lanes")));
+                        } catch (NumberFormatException e) {
+                            return Collections.emptyMap();
+                        }
                     }
                     for (Entry<String, String> entry : primKeys.entrySet()) {