Crews are set to start work today on a project to fix the notoriously jolting bump on eastbound Interstate 70 just west of the Eisenhower Tunnel.

The Colorado Department of Transportation will begin moving equipment out to the work site today. Lane closures could begin by midweek.

What has become known as the “big bump” – a reoccurring disturbance in the highway west of the tunnel – is caused by landslide activity underneath the highway. After years of paving over the problem area, CDOT implemented a long-term solution on the westbound lanes in 2010 that has proved effective. A similar fix will be applied to the eastbound lanes this summer.

Crews will complete the project from the inside out, initially closing the far left lanes of I-70 eastbound and westbound to begin work in the middle. The actual drilling work is set to start June 18 and continue up to the Fourth of July holiday, when work will move off the eastbound side to make way for the increased traffic.

“We’ll have three eastbound lanes,” CDOT Region 1 engineer Peter Kozinski said. “We might still have one of the westbound lanes closed, but we’ll definitely have three lanes eastbound going up the hill for the long weekend.”

The more extensive work is set to begin July 11. The project is not expected to cause full highway closures and officials said they plan to keep at least two lanes open in both directions throughout the project.

To eliminate the bump, crews will drill 187 holes 20 feet deep and 5 feet in diameter to remove 5-6 feet of asphalt, built up over years of repaving, and to gain access to areas with voids or unconsolidated materials. Crews will backfill the space with a lightweight material intended to reduce the driving force on the landslide.

New drains will also be put in place.

The project is expected to take most of the summer.

“We hope to have this buttoned up by September of this year,” Kozinski said. “It will be a function of how hard the drilling is and what we encounter down below. That’s the big challenge of working up in the High Country, is that you never know what you’re going to hit.”

Work likely will generally not continue on weekends. Officials said it is difficult for trucks carrying out material from the drill holes to merge with heavier weekend traffic and the work can distract drivers.

“We have people who get curious and not pay attention to the road and we create an unsafe condition,” Kozinski said.

Work may continue over a few weekends if necessary to keep the project on schedule, but it will not be over holiday weekends, he said.