Europe

Overnight subway service in London to serve 50,000 a weekend

  • Mayor of London Sadiq Khan, center, chats with passengers as he travels on a northbound Victoria line tube train during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)

    Mayor of London Sadiq Khan, center, chats with passengers as he travels on a northbound Victoria line tube train during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)  (The Associated Press)

  • Mayor of London Sadiq Khan, center,  touches his Oyster card at an entry gate at Brixton Underground Station during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)

    Mayor of London Sadiq Khan, center, touches his Oyster card at an entry gate at Brixton Underground Station during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)  (The Associated Press)

  • Mayor of London Sadiq Khan, left, shakes hands with Daniel George, a driver of the first Night Tube, in the driver's carriage of a Victoria line tube train at Brixton Underground Station during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)

    Mayor of London Sadiq Khan, left, shakes hands with Daniel George, a driver of the first Night Tube, in the driver's carriage of a Victoria line tube train at Brixton Underground Station during the launch of London's Night Tube Saturday, Aug. 20, 2016. The London Underground introduced limited overnight service Saturday, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Yui Mok/PA via AP)  (The Associated Press)

London's new overnight subway service has begun, with plans to host 50,000 riders each weekend.

London Mayor Sadiq Khan took the first Victoria line train on the new service early Saturday, chatting with passengers and marking the milestone. City leaders hope the new service will make the British capital a truly 24-hour city on the weekends and bolster its economy.

London already boasts a vibrant nightlife that attracts millions. But the service is also meant to serve doctors, cleaners and others who work graveyard shifts.

Police say they will be able to keep revelers in check.

Chief Constable Paul Crowther of the British Transport Police says "someone who's had a lot to drink at eleven o'clock is no different from someone who's had a lot to drink at three o'clock."