to the extant expressway on 29 March and a new section of the expressway opened on 29 October, extending the main section of the expressway north to Ashiro Interchange. The main section was extended north again on 20 October 1983 to Kazuno-Hachimantai Interchange. In 1984, it was extended north to Towada Interchange on 27 September. Koriyama-minami Interchange was added on 6 November. Hanamaki-minami Interchange was added to the extant expressway on 24 July 1986. Later, on 30 July the completion of the -long Sakanashi Tunnel allowed for the separate northern section of the expressway to be linked to the rest of the expressway. The expressway was completed on 9 September 1987 when it was extended south to its southern terminus at Kawaguchi Junction. Additional work after completion In October 2004, an experiment was conducted to test the viability of smart interchanges was conducted on the Fukushima-Matsukawa Smart Interchange, which was installed onto the pre-existing Fukushima-Matsukawa Parking Area in the city of Fukushima. After the experimental smart interchange was deemed successful, the Fukushima-Matsukawa Smart Interchange as well as sixteen others around the country were officially opened to traffic across the country in October 2006. Many sections of the expressway were damaged on 11 March 2011 during the 2011 Tōhoku earthquake and tsunami. The expressway reopened on 24 March 2011. List of interchanges and features PA - parking area, SA - service area, TB - toll gate References External links East Nippon Expressway Company Expressways in Japan Roads in Akita Prefecture Roads in Aomori Prefecture Roads in Fukushima Prefecture Roads in Gunma Prefecture Roads in Iwate Prefecture Roads in Miyagi Prefecture Roads in Saitama Prefecture Roads in Tochigi Prefecture 1972 establishments in Japan