OAKLAND (KCBS/ KPIX 5) — Workers at Alameda County’s AC Transit bus system have voted to authorize a strike if their union and the transit agency can’t agree on a new contract.

The AC Transit contract expires June 30, the same day as the labor deal for Bay Area Rapid Transit. BART workers were casting their own strike authorization vote on Tuesday.

Talks between AC Transit management and Amalgamated Transit Union Local 192, aided by a state mediator, remained ongoing despite more than 97 percent of ATU’s members voting to authorize a strike. An authorization vote doesn’t necessarily mean a walkout will happen, but it does give union leaders the authority to call a strike.