The expressway begins in southern
Miyagi Prefecture at a junction with the
Tōhoku Expressway and heads west, crossing over into Yamagata Prefecture. The route passes to the north of the
Yamagata city area and subsequently meets the
Tōhoku-Chūō Expressway. From here the expressway crosses mountainous areas of western Yamagata Prefecture before reaching the city of
Tsuruoka near the
Japan Sea coastline. The remainder of the expressway follows a northerly course paralleling the coastline to the terminus in the city of
Sakata. The route is incomplete between
Gassan Interchange and
Yudonosan Interchange which cuts the route into two physically separate sections. Travellers must use
National Route 112 to travel between the two interchanges. As of March 2008 there are no plans to make the Yamagata Expressway a single contiguous expressway. The expressway is 4 lanes from Murata Junction to
Yamagata Junction and 2 lanes for all other sections. The speed limit is 80 km/h for the 4-laned section and 70 km/h for the 2-laned sections. ==List of interchanges and features==