Polls are open from 7 a.m. to 8 p.m.
Post offices and liquor stores are open, and garbage is being collected in Pittsburgh. Pittsburgh Public Schools are closed.
Offices on the ballot include those for president, U.S. Senate, U.S. Congress and statewide for attorney general, auditor general, treasurer, 25 seats in the state Senate, and all 203 seats in the state House.
Allegheny County elections chief Mark Wolosik predicted that 70 percent of the county's 924,468 registered voters will cast ballots.
Voters will be asked -- but not required -- to provide photo identification. In an Oct. 2 ruling, a Commonwealth Court judge put off the state's voter ID requirements until the spring.
Allegheny County courts and its court records, treasurer and district attorney's offices are closed. City offices are open, but city council will not meet.