Trials of Kunming Metro Line 4 and Line 6 Phase II begin, China June 25, 2020 | Asia Pacific News The trials of Lines 4 and 6 (Phase II) of Kunming Metro have commenced. These trials are expected to conclude by September 2020. Line 4 spans 43.4 km and covers 29 stations. Line 6 Phase II spa... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password