In a major victory for building trade unions and a setback for non-union contractors, L.A. County’s Metropolitan Transportation Authority on Thursday approved a project labor agreement that would cover billions of dollars of future road and rail construction projects.

The 11-1 board vote means that contractors working on future Metro projects must hire workers through union hiring halls and pay into a special benefits fund. They must also hire residents from nearby local communities to do at least 30 percent of the construction work.

Project labor agreements place non-union contractors at a disadvantage, essentially requiring them to pay union-scale wages and pay benefits over and above what they may already pay their workers.

The Building Trades Council of Los Angeles and Orange Counties has been the major union group pushing for these agreements with public agencies throughout the county. So far, non-union contractors have been unsuccessful in their effort to stop the agreements from spreading.

The Metro agreement covers future road and rail projects with at least $5 million in construction costs, starting with the planned $1.7 billion Crenshaw Boulevard light rail line. Other projects include the planned Wilshire Boulevard subway extension and the $1.1 billion downtown subway project that would link several major transit lines.