MTA Chairman Joe Lhota resigned on Friday, barely 18 months into his second stint on the job.
Gov. Andrew Cuomo named Lhota MTA chairman in June 2017, a return to the role he left for the first time in 2013 to mount an unsuccessful bid for mayor of New York City.
Lhota was widely credited with cleaning up dirty stations and responding quickly to Sandy-damaged tunnels in the fall of 2012, during his first stint leading the agency.
This go-around, though, he has been under constant pressure over the condition of the subway system, the performance of the Long Island Rail Road and the financing for the agency's future needs.
In particular, from almost his first day on the job he sparred publicly with Mayor Bill de Blasio over who was responsible for fixing the subway system and how much the city was obligated to contribute to the costs.
But Lhota has touted the MTA's improvements over his tenure; subway delays hit a three-year low in September.
He said in a statement Friday, "I volunteered to become MTA chairman with the sole purpose of halting the decline of service and stabilizing the system for my fellow New Yorkers. The Subway Action Plan was developed in my first month at the MTA and it has successfully arrested the subway's decline."
Even as he held the MTA job, Lhota also retained his position as chief of staff at NYU Langone Health.
MTA leadership sent a letter to staff members Friday morning following Llhota's resignation. The letter reads in part: "We are extremely grateful for the steady leadership he provided during his tenure."
The letter added, "While Joe may be departing – our relentless focus on our customers remains unchanged."
MTA's acting chairman Freddy Ferrer said Cuomo shouldn't be in a rush to replace Lhota.
"I would urge the governor to take his time," he told News 4. "This is one of the most important appointments he will make, ever. This is the most important transportation organization on planet Earth. It's important that we get it right."