diff --git a/src/road.h b/src/road.h
index dbc8be6..3ca4c14 100644
--- a/src/road.h
+++ b/src/road.h
@@ -215,8 +215,16 @@ struct RoadTypeIdentifier {
        bool IsRoad();
        bool IsTram();
 
+       static RoadTypeIdentifier Unpack(uint8 data)^M
+       {^M
+               RoadTypeIdentifier rti;^M
+               bool ret = rti.Unpack(data);^M
+               assert(ret);^M
+               return rti;^M
+       }^M
+^M
        RoadTypeIdentifier(RoadType basetype, RoadSubType subtype) : basetype(basetype), subtype(subtype) {}
-       explicit RoadTypeIdentifier(uint8 data);
+       RoadTypeIdentifier() : basetype(INVALID_ROADTYPE), subtype(INVALID_ROADSUBTYPE) {}^M
 };
 
 /**