Downtown businesses should plan ahead for navigating a particularly intense period of construction along Interstate 235, say transportation officials.

Following the state high school basketball and wrestling tournament season early next year, repaving projects will begin between the Martin Luther King Jr. Parkway and East 14th/15th Street exits in March. It means that the downtown ramps will be intermittently closed as one side of the freeway or the other is closed for construction.

“I think this is probably the time that companies ought to really evaluate their plans in light of what’s going to be two significant construction years,” said Matt McCoy, vice president of the Downtown Community Alliance and co-chair of the Senate Transportation Committee. “We’re going to have 24 pretty significant months of construction affecting downtown. If it’s been a 4 or a 5 (on a scale of 1-10) the past year for downtown, it’s going to be a 7 or an 8 for the next two years.”

On Oct. 24 the Iowa Department of Transportation entered into a two-year, $93 million contract for the repaving of the portions of I-235 that provide downtown access.

“It’s a significant project; probably the biggest we’ve had,” said Bill Lusher, the IDOT’s field services coordinator for the I-235 project.

Last week, the first part of that project, installation of a new drainage structure on the east side of Keosauqua Way, began. That work will be followed by replacement of pavement on the east side of Keo, and then repaving of the west side.

In March, repaving work on I-235 itself will start on the westbound side of the highway at the MLK interchange, Lusher said. “We’re also hoping to get the eastbound side east of the (Des Moines) river done in 2006 as well,” he said. “By the end of 2006, we hope to have the westbound side from East 15th Street to about the Cottage Grove (Avenue) interchange, as well as a portion of the eastbound to East 15th completed. Then in 2007 we’ll have the eastbound from Cottage Grove to East 15th completed.”

The MLK and East 14th/15th Street exits can be considered the “bookends” of the downtown project phase, said Amanda Carstens Steward, a spokeswoman for the Greater Des Moines Transportation Management Association.

“During 2006, you’ll have MLK, Seventh or Third, and East 6th (as open exits) if you’re coming from the west,” she said. “Or from the east, you’ll have East 14th/15th, Keo Way and MLK. I think you’ll see a lot of people coming from the east will get off at East 14th/15th rather than going all the way through the construction zone; the same with MLK for people coming from the west.”

Lusher said DOT plans to try to keep the Third Street exit open as much as possible through 2006. At times when it does have to close, traffic will be shifted to the Seventh Street exit, he said.

“We’ll have an intense communication effort when that has to shift,” he said. “So we’re trying to bring more attention to how we notify people, and we’re going to try to use digital message signs on the highway more as well. That’s probably the most difficult part of the project; we don’t know exactly when those ramps will be available.”

Mike Ring, a city traffic engineer, said his employees have monitored traffic into downtown and adjusted signals in an effort to minimize bottlenecks on and off the I-235 exits for the past three years, and will continue to do so.

“It’s been a challenge,” Ring said. “We’ll have to do some signing and additional signal changes. The DOT is pretty heavily involved in that too.”

McCoy said downtown employers may want to consider implementing staggered shifts to allow workers to either work earlier or later hours to avoid the worst crunch times.

Steve Carlson, a spokesman for Wells Fargo Financial, one of downtown’s largest employers, said the company hasn’t made any adjustments to its employees’ work schedules and that it doesn’t plan on making any changes as the next construction phase approaches.

“The vast majority of our team members at Wells Fargo Financial downtown do work normal business hours, and it really hasn’t been an issue of great significance for us,” he said. “They’ve either found alternate routes or adjusted when they leave.”

Updated route information for I-235 users is available at www.i235.com. Commuters or downtown visitors can also use the Web site to register for e-mail alerts of when exits or routes change.