Yesterday's industrial action had a knock-on effect on the roads. The Metropolitan Police Service Helicopter released this picture of gridlock in Trafalgar Square last night.
Transport for London are operating a limited service on most tube lines, but they advise to check before you travel.
Union leaders were under pressure tonight to call off the strike after it emerged new peace talks would take place on Friday.
Bob Crow has told ITV News that he does not use ticket offices at London Underground stations.