Originally Posted by
evergrn
(All I want is a limited-stop train like Tokaido, Yokosuka and Ueno-Tokyo lines which all go the other way; currently the only option is NRT Express which only runs qhour from Shinagawa to Ikebukuro, and I refuse to take Yamanote. Ultimately this may require adding another track between Shinagawa and Osaki where the train can then pick up Saikyo track).
Google Map shows 4 tracks running between Shinagawa and Osaki. Maybe they won't need to build additional tracks for this purpose.