Hughes Access Road will be moved to the south, away from the Raytheon Missile System's plant on Tucson's South Side, to give the operation more buffer space, the Pima County Board of Supervisors decided Tuesday.

The board voted 4-1, with Supervisor Ally Miller opposed, for a $1.7 million planning and design contract as the first step in what will be an $8 million road realignment project, county officials said in a press release. The project will move the road 2,500 feet to the south, using 400 acres that the county purchased last year anticipating the realignment.

Raytheon, which has been vocal about encroachment and the proximity of the heavily traveled Hughes Access Road, responded positively to the county's move.

"Raytheon Missile Systems supports the Pima County Board of Supervisors' decision to fund design work on the realignment of Hughes Access Road near our plant site," company spokesman John Patterson said in an email. "Preventing encroachment will help us maintain our footprint here and grow if business conditions warrant expansion."

Money for the project is in the current county budget and comes from the county's share of state highway revenues, a spokeswoman said.

The proximity of Hughes Access Road has been a sore spot for Raytheon, which asked for years that it be moved. The road was built originally to give employees of the old Hughes Aircraft Co. a quick route to the plant from the east. Raytheon bought out Hughes in 1997.

Raytheon passed over Tucson for an expansion in 2010, saying the plant did not have enough room around it, including the Hughes Access Road alignment. The expansion and what eventually will be an additional 300 jobs went to Raytheon's Huntsville, Ala., facility.

"Simply put, there are too many drivers driving too close to existing operations that may be threatened by the high volume of public traffic," the county press release said. "Moving the road alignment helps address that issue, while providing Raytheon additional flexibility to preserve or expand their programs in the future."

Raytheon is the Tucson area's largest private employer with about 10,300 on its payroll.