SPRINGFIELD — Pioneer Valley Transit Authority buses throughout Hampden County could grind to a halt in the coming days if a strike is authorized by workers at the Springfield Service Area Garage, but PVTA’s operations throughout Hampshire County, including for the University of Massachusetts and the Five Colleges, would be largely unaffected.

Many of the more than 225 PVTA employees, including bus drivers, mechanics, supervisors and office workers, represented by Amalgamated Transit Union (ATU) Local 448-Springfield, overwhelmingly voted to reject a “final and best” contract offer and could walk off the job starting Sunday.

A strike date could be set during a vote Saturday morning, said Jim Harrington, financial secretary and business agent for the union. Harringon said he anticipates the strike would begin the following day if nothing changes later this week.

“We’re willing to sit down with them and continue to negotiate,” Harrington said.

But even if a strike begins, riders in and around Northampton and Amherst should see little impact.

“The Northampton and UMass Transit Garage will still be in service, as well as the shuttles and paratransit/dial-a-ride vans will service as well,” said Brandy Pelletier, a spokeswoman for PVTA. Hampshire County PVTA workers are represented by a different union, United Food and Commercial Workers Local 1459.

“This potential strike will only affect the Springfield Service Area Garage, which is managed by DGR Management Inc.,” Pelletier said.

Harrington said the express route that takes some riders from Springfield to Northampton via Holyoke Mall would be curtailed if a strike happens.

Jeff Jones, president of the United Food and Commercial Workers Local 1459, said his union would support the Hampden County union and, should a strike occur, its Hampshire County members would support them on the picket line. He said the Western Mass Area Labor Federation, of which he is also president, would also support a picket line.

The Local 1459 union will go into bargaining for a new contract next year, Jones said.

Union workers in Springfield don’t want to walk off the job for the sake of their riders, Harrington said, but the PVTA has forced their hand.

“We don’t want to shut it down, but we want to get the respect we’re owed. If PVTA won’t do that, they give us no choice but to take action,” Harrington said.

The union said PVTA management has refused to hold “meaningful talks” with workers.

Negotiations have been ongoing since March, with sticking points being wages, benefits and other key issues. Springfield Service Area Garage workers voted on Aug. 22 to authorize a strike if necessary.

Harrington said the union wants PVTA to “sit down with us and negotiate a contract with fair wages and benefits that recognizes the commitment and dedication of our members. Instead, they just slapped us in the face. They put an insulting offer on the table and walked away.”

Earlier this week, the PVTA summarized contract talks and warned that a strike may be coming.

In that announcement, the transit authority noted that it is not involved in any labor negotiations between its operations contractors and labor unions. Bus drivers and mechanics are employed by Springfield Area Transit Co., the fixed route contractor, and are not employees of the PVTA.

The state’s fiscal 2025 budget has allocated $10 million more than last fiscal year to all regional transit authorities for operating assistance. PVTA’s share of this is approximately $3 million. Based upon this increase to PVTA’s operating funds, DGR Management made a final offer to the union on Aug. 7 for a three-year contract.

According to PVTA’s statement, the offer includes, but is not limited to, wage increases of 10% over the three-year contract period. As proposed to the union, in year one the new top driver rate would be $32.81 an hour. In year two, the top driver rate would be $33.63 an hour, and year three, the top driver rate would be $34.47 an hour.

In addition to the wage adjustments, other highlights of the proposal include: an additional 5% on top of the regular hourly rate for all weekend hours worked; increased pension benefits; changes to salary schedules that would allow drivers to reach the top hourly rate after two years of work rather than the current five years, and the addition of vision insurance to the benefits package, the PVTA said.

“PVTA is cognizant of the possible ramifications the labor vote may have on our riders,” the statement reads. “Our passengers rely on PVTA’s transportation system to get them to work, essential appointments, school and more. Most importantly, few have other options to meet their transportation needs.”