Streets in Madrid could be shut down due to overcrowding in the city centre. The Spanish capital has activated the so-called ‘black level’ measure due to the high influx of visitors to the city over the Christmas period. Only implemented when there is exceptional saturation in public spaces and transport, the measure seeks to manage security and mobility in the city. Police will monitor the most congested streets from the sky using drones. Once the influx of people has reached a maximum, streets will be closed down, allowing pedestrians to leave, but not enter, the area. Around 450 municipal p…