There are a few residential areas along the line between Nara and Oji, which is a pastoral and paddy field zone, and heavy fog peculiar to Nara Prefecture occurs between Horyuji and Oji (particularly from early spring to around summertime) near the Yamato-gawa River and the tributaries, thus making warning colors necessary in order to enhance the visibility of the trains
奈良-王寺間では沿線に住宅が少なく、水田・田園地帯を進むが、法隆寺-王寺間では大和川やその支流で奈良県特有の濃霧（特に春先から夏頃まで）が発生するため、視認性を上げるために警戒色が必要とされる。