Traffic will no longer back up on Interstate 5 through Medford after six weeks of work to rebuild a three-quarter-mile stretch came to a close Friday night.

Traffic will no longer back up on Interstate 5 through Medford after six weeks of work to rebuild a three-quarter-mile stretch came to a close Friday night.

Motorists on the interstate will no longer have to wend their way through a maze of traffic cones, barriers and construction crews as they travel north or south, which led to delays of up to 20 minutes.

Oregon Department of Transportation spokesman Gary Leaming said the work, which shut traffic down to one lane in each direction, was completed according to schedule.

"We said six weeks, and today is the end of the six-week period," he said Friday.

During construction of the roadway from the viaduct to Barnett Road, ODOT anticipated there would be backups. But the department wanted to finish the $5 million project before the busy summer driving season.

Crews worked 22 hours a day ripping out cracked concrete in the slow lanes and laying down a thick layer of rock. All four lanes were then topped with 9 inches of asphalt.

On Friday night, the Oregon Department of Transportation was set to close the northbound on-ramp from the eastbound side of Barnett Road because the acceleration lane conflicts with slow-lane traffic on the interstate.

ODOT had hoped to keep the on-ramp open while work continued on the final phase of the $70 million south Medford interchange. However, construction interfered with motorists trying to get on the freeway.

"We've rendered that ramp unsafe," said Leaming. "We've just kind of eaten into that acceleration lane."

Signs have been placed on Barnett to alert motorists that the on-ramp is no longer available. However, the northbound ramp for westbound traffic over Barnett will remain open, but will close when the south Medford interchange fully opens in June.

Morning commuters can expect some slow-downs from 7 to 10 a.m. Monday through Friday next week when the northbound slow lane will be closed at the I-5 Bear Creek bridge to remove temporary bridge beams.

Leaming said the last major pour of concrete will take place soon on the interchange as the contractor, Wildish Standard Paving of Eugene, races to complete the new northbound on-ramp.

With the concrete in place, workers can concentrate on grading the approach to the freeway, then laying down asphalt.

Wildish Standard expects to complete the project by December, almost a year ahead of schedule. The interchange is the biggest highway project in the Rogue Valley since the interstate was built.

Once completed, the new interchange will completely replace the one at Barnett, which is 1,900 feet to the north.

Reach reporter Damian Mann at 776-4476 or dmann@mailtribune.com.