School bus drivers in East Hartford are preparing to vote on a strike after the union said DATTCO is not properly negotiating with the terms of its contract. The International Brotherhood of Teamsters Local 671 said the bus drivers — employed by New Britain-headquartered DATTCO — are considering going on strike if a contract is not settled. If the bus drivers vote to strike, transportation could be disrupted for thousands of students. School officials said they are aware and monitoring the situation.