The National Right to Work Foundation announced the results of the vote by 105 drivers in the Gateway School District, based in Monroeville.
The drivers aren't employed by the district but by Student Transportation of America. That company was hired by the district last July, and had recognized the Amalgamated Transit Union Local 1729 as the drivers' bargaining unit.
The drivers petitioned the National Labor Relations Board for the right to hold a secret ballot on whether to retain the union. The NLRB last month allowed the vote, during which 87 percent of the drivers voted to get rid of the union.
The drivers will now bargain directly with the company.