EVERETT — As Everett Transit faces a budget shortfall, the union representing bus drivers says terminating a cost-sharing agreement with Community Transit could avoid proposed cuts to service.

In the contract, Everett Transit contributes a portion of its sales tax revenue to Community Transit to run the Swift Blue line through the city. Without those funds, the line would end at Everett’s city limits, forcing commuters to transfer buses, according to Community Transit. The bus rapid transit line runs between Everett and Shoreline along Highway 99. During business hours on weekdays, buses arrive every 12 minutes.

“Our mandate is to move people around Everett, so we shouldn’t be paying people to move people out of Everett,” said Steve Oss, president of the Amalgamated Transit Union Local 883, which represents about 115 employees at Everett Transit.

Everett Transit is struggling to attract riders, as other transit agencies in the region expand. To overcome a budget imbalance, the agency has proposed doubling fares and cutting service by about 7 percent. If nothing is done, costs could exceed revenue by $1.6 million by 2020, according to the city.

As Everett deals with a larger citywide budget deficit, the mayor’s office said it’s considering restructuring or combining services, including transit and fire protection.

Oss worries the proposed cuts and fare hikes will impact ridership. He believes the city could avoid the cuts to bus routes if the agreement with Community Transit was ended.

“Anytime there is a change in service, you are disrupting people’s travel patterns and you will lose passengers,” he said. “And it takes a long time to get them back, and some of them you will never get back.”

Last year, the city’s transit agency contributed about $1.7 million from sales tax revenue to Community Transit, according to city spokeswoman Kari Goepfert. She said that paid for 43 percent of the entire Swift Blue Line service. A little less than half of the 30 stations are located in Everett.

That $1.7 million represents less than 10 percent of the total sales tax revenue collected by Everett Transit last year. Sales tax accounts for the bulk of the agency’s revenue. The same is true for Community Transit. The two agencies’ taxing districts don’t overlap.

If the agreement was terminated, the city wouldn’t be able to duplicate this service, Goepfert said.

And even if the city could, riders still would have to transfer at Airport Road and Highway 99, one of the biggest and busiest intersections in the region, according to Everett Transit Director Tom Hingson.

“If the agreement wasn’t signed, Swift wouldn’t be going into Everett,” said Martin Munguia, spokesman for Community Transit. “It really solved a big problem. When people had to transfer at the city line, it was a mess.”

Lizz Giordano: 425-374-4165; egiordano@heraldnet.com; Twitter: @lizzgior.