Both Metrobus and Fairfax Connector, Virginia’s largest local bus system, outsource operations to the same company. Transdev, a multinational transit contractor, is deadlocked in a labor dispute with 130 operators, mechanics and utility workers at Metrobus’s Cinder Bed Road bus garage in Lorton, Va.

Intentional or not, union members said Fairfax Connector buses are helping Transdev alleviate the impact of the worker strike. And what began Thursday as an isolated labor dispute involving Transdev and workers at a bus garage now threatens to entangle Fairfax County officials.

“My fear is that this is escalating to a point where we have the workers in [the Washington Metropolitan Area Transit Authority] and Fairfax seeking to do some kind of action now,” said John A. Costa, international president of the Amalgamated Transit Union, representing 190,000 transportation workers in the United States and Canada.

Mitun Seguin, a spokeswoman for Transdev, said Fairfax County’s Department of Transportation “determines service levels for its vendor runs, not Transdev.”

Robin P. Geiger, a spokeswoman for the Fairfax County DOT, said the extra bus service on Route 306 is not part of any strike contingency plan Transdev has with Metro. She said it is designed “to help customers and residents who may not have immediate transit alternatives in the area.”

Metro built the Cinder Bed Road bus garage two years ago to run 18 routes in Annandale, Fairfax, Old Town Alexandria, Springfield, Vienna and other mostly Northern Virginia areas. About 8,500 people on average ride the buses on weekdays, Metro said.

The transit authority awarded Transdev an $89 million contract in 2018 to run the garage, saying at the time that privatization would save $15 million over five years and prevent layoffs by avoiding paying garage workers pension and retirement benefits.

The deepening dispute involving the Cinder Bed Road workers highlights the complications of privatizing public services to save taxpayers money but often with lower wages and benefits than government jobs.

Union officials say operators at Cinder Bed Road make about $20 an hour while operators who work directly for Metrobus can earn up to $33 an hour.

This summer, the Fairfax County DOT also turned to Transdev. The company received a 5-year, $443 million contract with 10 optional years to operate the Fairfax Connector bus system, which handles about 30,000 passengers a day across nearly 90 routes.

Union negotiators say they plan to start talks soon for a new Fairfax Connector worker contract that calls for boosting pay and benefits. They said Fairfax County’s decision to increase service during the Metrobus work stoppage could impact discussions.

Fairfax County transportation officials said they’re just filling in a transit need for customers in the area.

Union officials and Transdev are set to restart talks with Cinder Bed Road workers on Thursday.

On Tuesday, the Fairfax County Board of Supervisors directed staff members to draft a letter to Metro, urging the agency to get both sides back into negotiations. Union officials said some supervisors have visited the picket line to support workers over the past few days.

“The strike, and the inconvenience it is causing, are unfortunate,” the board said in a memo calling for the letter. “It is clearly a direct consequence of WMATA’s decision to outsource bus operations in parts of Fairfax County.”

Hours later, Fairfax DOT provided a copy of the letter to WMATA that did not mention outsourcing but urged resolution of the dispute.

Metro General Manager Paul J. Wiedefeld also released a statement expressing frustration over route closures. “This disruption in service to our passengers is unacceptable,” he said. “I urge both TransDev and ATU officials to return to the negotiating table immediately. Both parties need to work diligently towards a collective bargaining agreement that restores service to our customers as soon as possible.”

Metrobus routes shutdown by the strike are 17B, 17G, 17H, 17K, 17L, 17M, 18G, 18H, 18J, 18P, 29C, 29G, 29W, S80 and S91 (TAGS). Routes 29N, 29K and REX operate on a limited schedule, according to Metro. The agency directed riders to its website, wmata.com/schedules, for schedules, alternatives and updates.