Operators of suburban SEPTA buses, trolleys, and the Norristown High Speed Line are considering a strike against the transit agency later this week, a top official of the union that represents them said Monday.

Members are especially concerned about long hours due to operator shortages, said Bruce Cheatham, president of United Transportation Union Local 1594. Operators can be drafted to fill overtime shifts if there are no volunteers, and many work seven days a week, he said.

“A lot of people don’t know that,” Cheatham said. “To me and to our members, it’s unsafe.”

It’s unclear how many total passengers would be affected by a strike.

The latest strike threat comes after SEPTA and its largest union, Transport Workers Union Local 234, reached agreement Oct. 29 on a two-year contract, avoiding a walkout that would have shut down transit on city buses, trolleys, and subways.

UTU’s contract is set to expire at 12:01 a.m. Friday. Members may vote this week to authorize a strike if an agreement or contract extension can’t be reached, Cheatham said.

Regional Rail service would not be affected if talks between the UTU and SEPTA break down. Those workers are represented by two other unions.

The two trolley lines in the Victory Division carried an average of 8,362 passengers on a weekday in 2019, and the Norristown light-rail line carried an average of 10,883, according to ridership reports. Ridership is climbing but is roughly half what it was before the pandemic. Bus ridership on affected routes was not immediately available.

“Negotiations are ongoing, and we’re optimistic an agreement can be reached without a strike,” SEPTA spokesperson Andrew Busch said. “We’re working toward a contract that’s fair to employees and financially responsible for the authority’s bottom line.”

The local represents 365 vehicle operators in SEPTA’s Victory Division. They run trolleys on the 101 line between the 69th Street Transportation Center in Upper Darby and Media; the 102 trolley to Sharon Hill; and the Norristown High Speed Line, a light-rail route between Upper Darby and Norristown.

They also drive buses on about 20 routes in Delaware County and parts of Montgomery and Chester Counties.

Some people still call these services the “Red Arrow Lines,” the nickname for the Philadelphia Suburban Transportation Co., which used a winged red arrow as its logo. Owners of the privately held company resisted the consolidation of the region’s transit services through the 1960s but sold their stake to SEPTA in 1970.

The United Transportation Union represented Red Arrow workers and has continued to represent many of their successors under SEPTA. Mechanics for the network of buses, trolleys, and the light-rail line belong to the Transport Workers Union Local 234, as do employees of other transit services in the suburban counties.

Grueling schedules have caused some operators to retire early and more recent hires to leave, Cheatham said. They’ve also worsened the shortage as some exhausted drivers use sick time to recover.

“It’s a mental strain — we’re getting a lot of callouts,” Cheatham said.

SEPTA managers acknowledge the burden operators have borne with longer hours and sometimes abusive passengers, issues facing many public transit agencies and transportation companies. The authority says it has hired and begun training new operators.

» READ MORE: SEPTA bus riders are frustrated by persistent delays. Officials say a shortage of drivers is to blame.

Under the agreement reached last month by SEPTA and TWU Local 234, workers will get 3% annual raises in each of the two years of the contract, as well as a one-time pandemic hazard bonus of one dollar for each hour worked between March 15, 2020, and March 15 this year, to a maximum of $2,200. They also won paid parental leave and the right for pregnant members to take leave under the disability insurance plan instead of using sick days.

Local 234 members have ratified their new contract. SEPTA’s board is scheduled to vote on it Thursday.