普通ＧＭ（１１）模型因预测值“上漂”现象而不能直接用于公路运输量长期预测。等维灰数递补模型通过缩小灰平面，提高灰平面白色度的方法，很好地解决了这一问题，用这种方法得到的长期预测值也较符合实际。 The general GM (11) model can not be directly used for the long-term prediction of the road traffic volume because of the drift of the forecast value. By using gray scale recalculation model to reduce the gray plane and improve the whiteness of the gray plane, this problem is solved well. The long-term prediction value obtained by this method is more realistic.