Index: trunk/test/atmsdriver/model/HighwaysTest.java
===================================================================
--- trunk/test/atmsdriver/model/HighwaysTest.java	(revision 228)
+++ trunk/test/atmsdriver/model/HighwaysTest.java	(revision 243)
@@ -94,4 +94,15 @@
 "  5 S @--";
 
+    public void testToJson() {
+        System.out.println("toJson");
+        Highways highways = new Highways(
+                "config/vds_data/highways_fullmap.txt",
+                "localhost", 8080);
+        highways.getHighwayByRouteNumber(5).stations.get(0).loops.get(0).vol = 1;
+        String result = highways.toJson();
+        System.out.println(result);
+        assertTrue(result.startsWith(expToJson1));
+    }
+    String expToJson1 = "";