Construction crews Tuesday put the finishing touches on a new five-lane Airport Boulevard overpass at Highway 101, which opened in time for this morning’s commute.

A new northbound onramp was also scheduled to open overnight, as well as a new left turn lane from the southbound offramp.

The debut of the overpass is a milestone in the $51 million project, which is helping reshape the transportation landscape in the booming area between Santa Rosa and Windsor.

“The project’s improvements will reduce travel delay, decrease congestion, improve operational clarity and efficiency, and improve traffic flow on local streets at the Airport Boulevard interchange and on Highway 101,” said Caltrans spokesman Allyn Amsk. “The overall goal is to create one full interchange instead of two partial interchanges at Airport Boulevard and Fulton Road.”

Construction is expected to continue until the end of the year. Eventually, the Fulton Road interchange, which is less than a half-mile from the Airport Boulevard interchange, will be eliminated.

Crews still need to demolish the old two-lane overpass and complete a new northbound offramp.

The new interchange is one of a handful of road, rail and air transportation projects in the area that is home to Airport Business Center and more than 5,000 jobs.

Caltrans plans to build a park-and-ride at the interchange to help commuters who carpool to work.

Airport Boulevard west of Highway 101 is scheduled for a makeover. The Sonoma County Transportation Authority, using state, federal and local Measure M sales tax money, plans to widen the street to five lanes between Ordinance Road and Aviation Boulevard.

Other phases include connecting Laughlin Road and Brickway Boulevard and building a new bridge over Mark West Creek to provide a southern entrance to the airport industrial area. Construction could start in 2016.

The Sonoma-Marin Area Rail Transit authority is building a commuter rail station at Airport Boulevard about a half-mile from the Highway 101 interchange. The passenger train service, expected to start in late 2016, will link the Airport Boulevard area with San Rafael and, eventually, the Larkspur ferry terminal.

At the western end of Airport Boulevard, Charles M. Schulz-Sonoma County Airport is also getting an overhaul. A project to extend and decouple both runways, expected to wrap up at the end of the year, will help attract airlines serving eastern destinations, airport officials say.

The Airport Boulevard interchange project is being built by Ghilotti Construction Co. of Santa Rosa. It also includes soundwalls at various places along Highway 101 in Windsor.

A follow-up landscaping project is planned but not yet funded.