BONSALL, Calif. - State Route 76 will get two new westbound lanes between Bonsall and Oceanside on Thursday.

The new lanes are part of a project to widen the state road across northern San Diego County, according to San Diego Association of Governments and Caltrans.

The work on the middle section of SR 76 is expected to cost $171.4 million by the time it's completed.

The western end of the highway, which runs through Oceanside to Interstate 5, opened 13 years ago. Work is scheduled to begin later this month on the eastern end, running to Interstate 15, which will take about three years.

"Widening state Route 76 has long been a priority for SANDAG and for North County," SANDAG Chair and Encinitas Mayor Jerome Stocks said. "It's exciting that this milestone has been reached, but this is just the beginning of the efforts to reduce traffic congestion along this key east-west corridor."

The new westbound lanes run from Sweetgrass Lane in Bonsall to Melrose Drive in Oceanside.

Work on eastbound lanes is continuing, and those lanes are expected to reopen in November.