JR East Japan uses the E235 series new car of Yamanote Line to carry ATO automatic driving system for short, and carries out fully automatic driving test from departure to parking during the period after the last bus. Although the existing Yamanote Line has been equipped with ATC automatic driving control system and TASC fixed position stop system as the means of speed control and platform parking, acceleration and deceleration still depend on manual driving control, and ATO automates these parts. As for the reason for choosing Yamanote Line, it is also because Yamanote Line is a relatively simple line in JR East Japan, and the relevant platforms have already started to prepare gates. There is only one grade crossing at the same time, which is more suitable for testing.
Image source: Wikipedia/Author: Abezori2525
News related sources: Asahi Shimbun