On the same date, an above-ground segment linking the tunnel to the Kumanochō Interchange in Itabashi and Toshima opened.
Fire-safety equipment includes infrared sensors, fire extinguishers, foam sprayers, and pushbutton alarms.
The Ohashi Junction in Meguro, connecting the tunnel to the Shibuya Route, required construction of stacked elliptical ramps 400 meters (1,300 ft) in circumference and 175 meters (574 ft) in diameter, similar in size to the National Stadium track.
For soundproofing reasons, the junction was encased in over 120,000 cubic meters (160,000 cu yd) of concrete.
The structure was used as the centerpiece of an urban planning project that includes the Meguro Sky Garden park and several high-rise condominium towers.
The tunnel runs parallel to the Ōedo Line, along a segment between Nakai and Nishi Shinjuku Gochome Stations.