Vineyard Transit Authority bus drivers voted on Monday evening to authorize a strike, if they cannot reach agreement on a new contract. The drivers, organized under the Amalgamated Transit Union, have been locked in bargaining talks with Transit Connection Inc., the company that contracts with the VTA to hire and manage drivers, for months.

The two sides are on the Island this week, for a fifth bargaining session in the past seven months. A federal mediator joined the talks in February.

Issues on the table include wages and working conditions.

A strike authorization vote does not mean a job action is imminent.

“The members are very frustrated obviously,” said Bruce Hamilton, an international vice president for the union who is participating in the talks. “They did take a vote to authorize the bargaining committee to call a strike if we cannot reach a settlement. There is no time placed on that, but it shows that they’re very frustrated at the lack of progress.”

The union says it is seeking fair discipline and due process, health and safety improvements, and wage increases.

Transit Connection president Ed Pigman said the company continues to negotiate in good faith.

“We’re having meaningful discussions, it will depend on how those work their way through,” Mr. Pigman said. “It’s obviously been some tough going.”