London Underground experienced its busiest day in history on 4 December as 4,821,000 journeys were made on the Tube, smashing the previous record of 4,795,000 commuters set on 27 November 2015. Eighteen of the top 20 busiest days ever recorded on the Tube are in 2015.

Since 2001, the rate of customer journeys on the Tube has soared by a third and Transport for London (TfL) has said that it expects the record to be broken again before the end of the year. "The Tube continues to break records for the number of customers we're carrying as London's economy and population keeps on growing," London Underground Managing Director, Nick Brown said.

"The current work to improve London Underground is one of the largest programmes of infrastructure investment in the world," he added. "We will continue to invest all our income in modernising the service, improving reliability, train capacity and frequency, and upgrading major stations to provide a Tube network fit for the world city it serves."

The first week of December was the busiest in the Tube's 152-year history with 28.76m journeys, beating the October record of 28.69m. London is Europe's fastest growing city with a population of 8.6m people. That number is projected to rise to nine million by 2018 and 10m by 2030.

On 7 December, commuters were finally able to board and disembark from the Central line at Tottenham Court Road after a year of closure. It was shut as part of a £500m upgrade of the station and improvements include a 15-metre glass entrance, step-free access lift shaft, refurbished elevators and refitted platforms. A new ticket hall (five times larger than the old one) and carefully restored Paolozzi mosaics part of London Underground's heritage will also be completed in 2016.

Modernisation work at Tottenham Court Road and Bond Street stations were blamed after it was revealed that Oxford Circus Station was temporarily shut 113 times in a year due to overcrowding. The figures on the capital's busiest station (nearly 100m passengers entered or left Oxford Circus in 2014) were released earlier this month.