A busy I-295 northbound off-ramp in Yarmouth will be closed next month so crews can begin work on an interchange project that’s designed to improve access and safety, according to the Maine Department of Transportation.

The DOT, which is scheduled to formally announce the $6.1 million road project on Wednesday, will close the Exit 15 northbound off-ramp from mid-March until mid-June. About 5,000 vehicles a day use the off-ramp and will be shifted to exits 10 and 17 and onto Route 1, which runs parallel to the interstate.

The existing southbound on- and off-ramps and will remain open throughout the construction project. There is no northbound on-ramp at the exit, though one will be added.

Crews have already begun clearing trees and brush from the site, although major construction is not expected to begin for a couple weeks.

The first phase calls for blasting and removal of about 80,000 cubic yards of earth, bedrock and old roadway, project manager Ernie Martin said in a statement Tuesday.

“Even though the blasting episodes are over in seconds, we thought it best to divert traffic from the immediate area,” Martin said.

When completed, the project will include a new northbound on-ramp, improving access to the highway and alleviating strain on Route 1 for travelers seeking a way to get on the highway, according to the DOT. The project also will feature a new 300-vehicle commuter parking lot near the southbound on-ramp, which will be reconfigured to correct safety flaws identified in a 2010 study of I-295 between Scarborough and Brunswick.

During a three-year period earlier in the decade, nine accidents were recorded at the interchange, five of which caused injuries to motorists or passengers.

The most dangerous section of roadway was found to be the southbound on-ramp, where cars attempting to enter I-295 meet vehicles already on the highway at a curved angle. The new entrance to the highway will be parallel to the flow of traffic and allow for smoother merging, said Nat Tupper, Yarmouth town manager.

The overall project “will make a difference in how Route 1 operates for local businesses,” said Tupper. “You’ll have less through traffic trying to get to the interstate.”

While the inconvenience will persist for more than three months for local residents, the Exit 15 off-ramp is scheduled to re-open in time for the Independence Day weekend and the annual Yarmouth Clam Festival in late July.

Work on the interchange and lot will continue after the exit re-opens and the entire project is expected to be complete by November, according to the state.

During construction, Yarmouth-bound motorists traveling north will be advised to use a six-mile stretch of Route 1 accessible from exits 10 and 17. Crews will install temporary traffic signals to usher vehicles onto and off of Route 1 during the construction at the two interchanges.

Staff Writer Matt Byrne can be contacted at: 791-6303 or at: [email protected]

Correction: The headline for this story was revised at 11:20 a.m., Feb. 27, 2013, to state that the $6.1 million road project will be completed in November.