Blasting along Highway 69 could cause traffic delays this summer as work crews begin to widen another 28 km of highway to four lanes.

But unlike previous construction on the busy north-south route, blasting for the new lanes south of Sudbury is happening right beside the existing highway.

"There is a lot of equipment moving between worksites on the highway," said Gordon Rennie, a spokesperson with the Ministry of Transportation.

"The speed limit is reduced to 70 km/h and 60 km/h in different locations. So we just really encourage motorists coming north or south on the highway to give themselves extra time."

Rennie said all available resources are being dedicated to the construction, but it's not yet clear if it will be finished by the deadline. The entire four-laning of Highway 69 was projected to be complete by 2017.

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The Ministry of Transportation's John Cimino is overseeing the project to four-lane Highway 69. (Megan Thomas/CBC)

In the meantime, it could a bit of be an exercise in patience for those travelling the highway this summer, as more than 600 workers blast through and remove a couple of million tonnes of rock.

"We have removed a lot of the organic material, on the rocks and we are getting ready to drill and eventually blast all the rocks," said John Cimino, who is overseeing the project for the Ministry of Transportation.