code: @Pure
  	public static String getPreferredAttributeNameForTrafficDirection() {
  		final Preferences prefs = Preferences.userNodeForPackage(RoadNetworkConstants.class);
  		if (prefs != null) {
  			return prefs.get("TRAFFIC_DIRECTION_ATTR_NAME", DEFAULT_ATTR_TRAFFIC_DIRECTION); //$NON-NLS-1$
  		}
  		return DEFAULT_ATTR_TRAFFIC_DIRECTION;
  	}
docs: Replies the preferred name for the traffic direction on the roads.
  
  @return the preferred name for the traffic direction on the roads.
  @see #DEFAULT_ATTR_TRAFFIC_DIRECTION