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。