There has been a lot of railway construction going on recently around Shibuya station. The Fukutoshin （副都心線） line construction was completed between Wako and Shibuya linking through Ikebukuro （池袋） and Shinjuku san-chome （新宿三丁目）.
The train line is buried underground in large tunnels, which is where most of the construction took place using large cylindrical cutting machines. Above ground there was some disruption to Meiji Dori (明治通り), the road above where most of the route runs, for access to the underground construction areas.
At the moment, construction is moving ahead on the southern extension of this line which will see the current above ground station for the Toyoko Line be moved underground and linked up with the Fukutoshin Line. When this is complete in 2012 you will be able to ride from Wako-shi passing through Shibuya and straight on to Yokohama.
This linking up or amalgamation of multiple train lines has been going on for a while as the Tokyo train system expands to meet consumer demand for more trains and better connections.
With the Toyoko Line platform moving underground, it can’t be long before plans for the redevelopment of Tokyu Department Store above Shibuya station are put into motion.