By early 2018, motorists driving a 14-mile stretch of Interstate 90/39 from Beloit’s north side to the north end of Janesville will see a major lane expansion project in full swing.

In mid-October, the Wisconsin Department of Transportation plans to open a crossover near the Racine Street exit in Janesville to shift traffic from the northbound lanes to the southbound side as contractors remove pavement as part of the plan to beef up the Interstate from four lanes to eight along a 6-mile stretch between Highway 14 and Avalon Road.

Then, early in 2018, the DOT will open a second northbound-to-southbound crossover for another 8-mile stretch between Hart Road near Beloit and Avalon Road.

The DOT bid out that work Aug. 8 and awarded the project a few weeks ago, a contractor on the project said.

The state detailed the two projects’ tentative timelines during a public information session held Tuesday in Janesville.

Once the twin projects are underway, they will turn a 12-mile stretch of I-90/39 between the two cities into a continuous work zone for more than two years as crews first expand the northbound side of the Interstate in 2018, then the southbound lanes.

The two projects, which cost about $100 million total, will roll out through part of 2020. They’re part of the larger, 45-mile mega-project to expand the Interstate from four lanes to six between Beloit and Madison and to eight lanes through Janesville.

In all, the project is scheduled for completion by 2022.

The Janesville-to-Beloit tear-up will be similar to lane expansion work that has been going on this summer in the north lanes of I-90/39 north of Edgerton.

Crews will begin staging in Janesville for the northern leg of the project over the next few weeks, said Pat Gardner, a project manager for Rock Road Companies. Rock RoadTM won DOT contracts for both segments of the expansion between Janesville and Beloit.

The DOT has penciled in the two projects even as the state continues to hash out its 2017-2019 biennial budget.

Much of the funding for the projects is coming from “base-level” state road budget funds that kicked in in July as the 2015-17 budget ended, DOT spokesman Steven Theisen told The Gazette earlier this year.

The Janesville-to-Beloit stretch of Interstate expansion awarded to Rock RoadsTM this month comes out of a $175 million pot of money the state is divvying between major road projects statewide.

Theisen said Thursday that the state has essentially allocated funding for the Janesville portion of the I-90/39 project out of a baseline funding model based on the 2015-17 biennial budget.

A $40 million cut of the Janesville section of the project is being paid through a federal highway grant designed to bolster major highway projects, Theisen said.

That this 13-mile stretch of the I-90/39 expansion in Rock County is already funded makes it more likely the project will remain on schedule, despite some warnings earlier this year from Gov. Scott Walker that the state might have to delay parts of some major road projects if the state Legislature didn’t get a state budget and roads funding in place by late summer.

Walker and lawmakers said Tuesday they had an agreement in place for the 2017-19 budget. They expect to be able to vote on the plan next month.