Mr. Corbett said New Jersey Transit had experienced a “dramatic 88 percent reduction in systemwide ridership” since March 9. He said revenue had fallen in line with ridership and that the agency expected “this precipitous drop to continue” as fewer riders to buy monthly passes.

New Jersey Transit’s schedule changes apply only to the agency’s trains and affect all lines except for the Atlantic City Rail Line, and do not affect buses or light-rail systems.

On weekdays, eight daily runs will be added to the usual weekend schedule on the Morris and Essex line between Dover and Hoboken. Service on the Gladstone branch will be unchanged.

Three more correction officers test positive, officials say.

The city’s Department of Correction confirmed on Thursday that two correction officers and a captain had tested positive for the coronavirus.

The announcement came a day after an inmate, a man in his 30s, at the Rikers Island jail complex tested positive, as did a correction officer who was assigned to a security checkpoint there. Eight other inmates who were in contact with the man and had shown symptoms of the virus have been placed in isolation at a Rikers hospital unit.

The mayor’s office is trying to identify Rikers inmates who could be released early in hopes of stemming the virus’s spread among the roughly 5,400 people in the city’s custody. Mr. de Blasio said on Wednesday that inmates with underlying health conditions could be eligible.

On Thursday, the mayor said that the city had identified 40 inmates who could be released, pending the approval of other criminal justice authorities.