SEPTA workers could strike as soon as Friday | Here is the potential impact for Philadelphia riders

PHILADELPHIA (WPVI) -- Time is running out for SEPTA to reach a new contract deal with its union workers.

Members of Transport Workers Union Local 234 could hit the picket line as soon as Friday if no deal is reached by then.

They voted last month to authorize a strike.

SEPTA said Wednesday that it expects negotiations to continue through Thursday.

The contract expires at 11:59 p.m. Thursday. SEPTA said it is not yet definite that the union will strike, saying that the decision will be up to union leaders.

SEPTA spokesperson Andrew Busch said that if the union does call a strike, it would shut down all bus, trolley and subway/el service within the City of Philadelphia.

Regional Rail would run into the city as normal, and the suburban transit services - buses, Routes 101 and 102 trolleys, Norristown High Speed Line - would operate.

SEPTA has released a guide with travel times for riders in the event of a strike. That guide is posted here at SEPTA.org.

After the strike authorization vote last month, union representatives said they are fighting for more pay and improved safety and security.

Members of the union said in October that ongoing violence around the city is becoming a major problem for them.

"Seems as though we are not as important as they like to say we are because if they were, safety would be paramount," said Andre Jones Sr., vice president of TWU Local 234, said at the time.