Thousands of residents and commuters are getting the green light to travel on Orangethorpe Avenue.

After a final inspection Wednesday, Orangethorpe Avenue is expected to open to traffic between Chapman Avenue and Kraemer Boulevard on Thursday.

“There will now be three lanes in each direction over the rail crossing bridge at Orangethorpe,” Orange County Transportation Authority spokesman Eric Carpenter said.

Commuters will also be able to use Crowther Avenue, though two eastbound lanes at Miller Street will remain closed while crews work on an underground pipe. That work is expected to be completed by August.

The Orangethorpe Avenue overpass is part of the $635 million OC Bridges Project, which is building seven overpasses and underpasses that should improve traffic flow by separating roads from train tracks that run through Anaheim, Fullerton, Placentia and Yorba Linda.

Some 70 trains chug through the area daily, and that number is expected to increase to nearly 130 trains by 2030, according to the transportation agency. As the bridges are completed, drivers at key north-south crossings will no longer have to wait out passing trains.

Bridges at Placentia Avenue and Kraemer Boulevard were the first to be completed. The Tustin Avenue/Rose Drive overpass opened in December. Construction continues on three more bridges: Lakeview Avenue, Raymond Avenue and State College Boulevard.

The project is expected to be completed in 2018.

Funding for these projects comes from local tax dollars, state funds and federal funds.

Contact the writer: 714-796-7868 or desalazar@ocregister.com