A three-year-long road construction project that will significantly change traffic patterns on Bend’s south end — and bring Third Street its first-ever roundabout — is set to begin this summer.

A joint effort between the city and the Oregon Department of Transportation, the $27.5 million Murphy Road Overcrossing project is intended to address two concerns — the hazardous, signalized intersections where the Parkway meets Third Street and Pinebrook Boulevard, and the lack of east-to-west connectivity on the south side of town. Along with removing both signalized intersections, the project would extend Murphy Road over a bridge across the Parkway through to Brooks-wood Boulevard.

The Third Street roundabout would be positioned roughly between the Les Schwab Tire Center and the Arco station and would be one of three roundabouts included in the project.

Traffic turning west out of the Third Street roundabout would be directed over the bridge above the Parkway, meeting Brookswood at a roundabout at Larkwood Drive.

Traffic headed right from Third Street would travel on a newly designated section of Murphy Road south of the Arco station that would feed into another new roundabout at the intersection of Murphy and Parrell roads. The intersection between the existing section of Murphy Road and Third Street would remain, but the signal at the intersection would be removed.

All of the funding for the project is being provided by ODOT, with $25 million coming through the Oregon Jobs and Transportation Act, a measure adopted by the 2009 Legislature. The act created a 6-cents-per-gallon gas tax, generating an estimated $300 million a year to finance modernization and improvements of Oregon roads, highways and bridges.

The Murphy Road Overcrossing project is one of four Central Oregon projects funded under the Oregon Jobs and Transportation Act. Another $2 million was set aside for now mostly complete improvements to U.S. Highway 97 between Redmond and the Crooked River Gorge bridge, and $5 million was reserved for the completion of the Redmond reroute. ODOT spokesman Peter Murphy said ODOT will use a portion of the reroute funds to repave a section of Sixth Street, which functioned as the highway until the reroute opened in 2008, though plans to extend the reroute further south are on hold.

Murphy said contractors will begin bidding on the overcrossing project in the spring, and construction should begin in July. Until a contractor is selected, it’s too soon to know what elements of the project will be built when, Murphy said, though it’s likely the two overpasses above the parkway will be some of the earliest construction. Drivers will experience delays at times over the three years of construction, although Murphy expects they will be minimal.

“We don’t know what those are going to be until the contractor is on the job, but much if not most of the work is going to be done at night; much if not most is not on the current alignment — it’s on dirt,” he said.

Nick Arnis, the city transportation engineering manager, said he’ll work closely with the contractor to develop a traffic control plan for the area surrounding the Third Street and Murphy Road intersection.

“We’re not going to shut it down completely like we did last summer with the roundabouts; you just can’t do that here,” Arnis said. “We’re not going to do that; there’s too many businesses, and it’s too busy an area.”

The earliest work on the project will not involve roads at all, but sewers.

Heidi Lansdowne, the project manager for the city, said sewer lines near Third Street will need to be moved so that city crews will still be able to access them once the on- and offramps are constructed. To the east, where the Murphy Road extension will cross through the Pinebrook subdivision, construction will destroy the drainfields for a handful of homes still using septic systems. A sewer line extension will be built to connect the affected houses to the city sewage system, Lansdowne said.

Completion of the project will mean the elimination of some routes drivers use today. A median will prevent drivers from crossing the Parkway on Pinebrook Boulevard, with traffic limited to right-in, right-out turns on both sides of the Parkway. Romaine Village Way will no longer connect to Highway 97, due to its proximity to the onramp that will move southbound drivers from Third Street to the highway. The section of Murphy Road between Parrell Road and Third Street will remain, Arnis said, but is likely to be renamed and narrowed for low-speed local traffic.