The bus and rail sector has become a 'value trap' following a 45% rally during the past year, says US broker Smith Barney, which has cut its recommendations on the big operators because they have risen far enough. It has downgraded Arriva, up ¼p to 570p, FirstGroup, 8¾p off at 370½p, and National Express, 41½p lower at 895½p, from hold to sell and repeated its sell recommendation on Stagecoach, down 2¼p at 120¾p.