A Black River Falls company started work Tuesday on a $900,000 temporary fix to westbound Interstate 94 to allow two-way traffic between Milwaukee and Madison, which officials say should end a 115-mile detour by Friday.

As construction crews began the work Tuesday evening, traffic traveling east backed up more than two miles at the Lake Mills exit. State officials expect similar delays this afternoon.

The work will provide for two asphalt crossover areas, one just west of Johnson Creek and the other just east of Lake Mills, where the rising waters of the Rock and Crawfish rivers have threatened to swamp bridges and the northern portion of the roadway. A 28-mile portion of the westbound highway, which allows for traffic from Milwaukee to Madison, has been closed since last week.

Transportation Department Secretary Frank Busalacchi said the state used an emergency contract to have the crossovers built across the Interstate median. That will allow one lane of traffic going east and one lane going west for four to five miles on the southern portion of the highway. Traffic lanes will be separated by plastic wands and painted stripes.

Busalacchi said the $896,000 is available in the budget but will have to be replaced, either by federal emergency assistance, state taxpayers or other sources. "We'll sort this out later," he told reporters near the threatened bridge over the Rock River near Johnson Creek. "We may have to go back to the Legislature and ask for money ... $900,000 is not exactly the end of the world."

The crossover construction would become irrelevant if the flooding eases quickly and I-94 can fully reopen, he acknowledged. "We don't know what this river is going to do. ... We've just got to make a decision here, and that's what I'm doing," Busalacchi said.

Busalacchi said I-94 is a vital state artery that cannot remain closed.

The secretary said he didn't expect already scheduled road repair projects to be delayed. "We'll get through the summer just fine," he said. "If we do end up slowing things down, it will be for a good cause."

DOT Southeast Region Director DeWayne Johnson said the $896,000 price tag on the crossover is merely an estimate that could go up or down depending on the volume and type of materials used.

The price tag was not negotiable, largely because of the pressure to fix it fast, Johnson said. "The time element is what's driving this," he said. "This is the right thing to do."

Busalacchi said Hoffman Construction Co. was picked because the company could finish the work quickly. "They're a company that can react quickly so we picked them," he said. Neither Johnson nor Busalacchi could say how much a highway crossover project would cost if it were competitively bid.

The closed stretch of westbound I-94 has led to a lengthy detour for drivers coming from Milwaukee to Madison — all the way to Beloit by taking Highway 83 to I-43 to I-39-90, a 115-mile detour compared to the normal 45-mile trip.

The crossover section will present a bottleneck during rush hours, he said, "but we won't have a 100-mile detour."

Matthew Murphy, a DOT bridge maintenance engineer, said the two westbound I-94 bridges that are shut down were originally built for what was then Highway 30. That's one reason they are lower than the newer eastbound bridges, which were built in the 1960s along with I-94.

Unlike the newer bridges, the westbound ones sit so low that the water has risen above their steel girders — and they are on the upstream side which puts them more at risk, he said.

Dennis Shook, a regional communications manager for the state Department of Transportation, said officials are not worried the Interstate's eastbound lanes are in danger of being overtaken by water the same way the westbound lanes have — as long as there aren't more heavy storms like the ones a week ago.

"If everything remains just status quo, we'll be fine," he said.

State Journal reporter Chris Rickert contributed to this report.