Preliminary data shows the New York Metropolitan Transportation Authority (MTA) reached a new modern record when 6,217,621 customers entered the MTA New York City Transit subway system on Thursday, Oct. 29. The subway system carried 50,000 more customers that day than at its previous record peak, just one year earlier.

“The relentless growth in subway ridership shows how this century-old network is critical to New York’s future,” said MTA Chairman/CEO Thomas F. Prendergast. “Our challenge is to maintain and improve the subways even as growing ridership puts more demands on the system. We are doing it thanks to the MTA Capital Program, which will allow us to bring meaningful improvements to our customers, such as real-time arrival information on the lettered subway lines, cleaner and brighter stations with new technology like Help Points, modern signal systems and almost 1,000 new subway cars.”

The new modern ridership record was set on the last Thursday in October, traditionally one of the system’s busiest days. The previous record of 6,167,165 was set Oct. 30, 2014. The new record day was one of five days in October when ridership exceeded the prior year’s record, and was one of 15 weekdays with ridership above six million. Daily subway ridership records have been kept since 1985, but the new record is believed to be the highest since the late 1940s.

October 2015’s average weekday subway ridership of 5.974 million was the highest of any month in over 45 years, and was 1.4% higher than October 2014. Approximately 80,000 more customers rode the subway on an average October 2015 weekday than just a year earlier — enough to fill more than 50 fully-loaded subway trains.

Ridership surged on the weekends as well, with the average weekend ridership higher than any October in over 45 years. On Oct. 31, 2015, the day of the Village Halloween Parade and a Mets World Series game, 3,730,881 customers rode the subway — making it the fifth-busiest Saturday on recent record.

Between 2010 and 2014, the subway system has added 440,638 daily customers, roughly the equivalent of the entire population of mid-sized cities like Miami or Raleigh, N.C. More customers have led to additional crowding on some lines, creating conditions in which trains are more likely to be delayed and delayed trains in turn affect more customers than in the past.

As ridership continues to soar, performing necessary maintenance and improvement work while providing good service has become a growing challenge. Work that is typically done overnight and on weekends now affects more riders as ridership grows during these off-peak hours.

The MTA has introduced short-term measures to improve train service this year, including Platform Controllers at strategic locations to help move customers on and off trains quickly, “step aside” boxes to encourage letting customers off the train before boarding, and staging more maintenance crews in locations to respond to problems quickly.

In the longer term, the MTA is adding subway capacity by installing communications-based train control (CBTC), a modern signaling system that allows trains to operate more closely together. CBTC is in operation on the L Subway line and is being installed on the 7 Subway line, while the next MTA Capital Program will expand CBTC work in Queens, the Bronx and Manhattan.

When the first phase of the Second Avenue Subway is completed next year, it will serve more than 200,000 customers each day and decrease crowding on the adjacent lines by as much as 13%, or 23,500 fewer customers on an average weekday.