An electronic sign warns of strike action on Southern Railway services, at Victoria Station in London, Tuesday, Dec. 6, 2016. Southern strike action will coincide with disruption to the tube network. The RMT has also announced 24-hour walkouts by train drivers on the Piccadilly and Hammersmith & City tube lines from 21.30 on Tuesday, Dec. 6 in separate and unrelated disputes. (AP Photo/Kirsty Wigglesworth)