Route 4 runs west from Miyakezaka Junction (with the Inner Circular Route) in Chiyoda-ku and runs for 8.44 miles (13.5 km) through Shinjuku-ku, Shibuya-ku, and Suginami-ku.
Route 4 commences at Miyakezaka Junction (alongside the Inner Circular Route) in Chiyoda-ku, covering a distance of approximately 8.44 miles (13.5 km) as it passes through Shinjuku-ku, Shibuya-ku, and Suginami-ku.