Some facts about the nation's largest mass transit system, the contract negotiations between New York City's Metropolitan Transportation Authority and the Transportation Workers Union, and a threatened strike.

--Riders: 7.2 million trips a day on subways and buses.

--Workers: 34,000 represented by the union.

--Deadline: 12:01 a.m. Monday.

--The Law: State law says public employees who strike will be fined two days' pay for every strike day, union will face separate fines. A judge's ruling Friday banning workers from striking could mean additional fines and possible jail time. The city wants fines for the union starting at $1 million a day and doubling each day a strike continues, and for each striking worker starting at $25,000 and doubling daily.

--Strike Cost: Mayor estimates $100 million to $350 million a day in lost business, retail and sales taxes and police overtime.

--Strike History: City's last transit strike lasted 11 days in 1980. Union struck for 12 days in 1966, prompting enactment of the state law.

--Provisions: Residents urged to walk or bike to work; taxis asked to pick up multiple fares; cars required to carry at least four people to enter or leave Manhattan on weekdays.