APPLETON, Wis. (AP) Part of U.S. 41 will eventually be designated an interstate, bringing all the improvements that go with it.

U.S. Rep. Tom Petri, R-Fond du Lac., inserted language in a 2005 federal highway bill to designate U.S. 41 as an interstate. Don Miller, director of project development of the state Department of Transportation, said it is preparing to launch a study to determine what improvements are needed for the upgrade.

The exact timeline for the change and the cost are unknown.

“Interstates are the top-quality roads, which is the safest design standard in the United States. It would be safer. I’m sure it would end up saving lives and reducing accidents,” Petri said.

The designation would apply to the length of 41 between Milwaukee to Green Bay.

State Department of Transportation officials said that once the study is done, they plan to craft an agreement with the U.S. Department of Transportation in early 2008 to move the project forward.

Miller said new interstate signs could be placed on the highway in 2009 at the earliest with additional improvements to follow.

Wisconsin has 743 mi. of highway on Interstates 39, 43, 90, 94, 535, 794 and 894.

According to the state DOT, interstates make up less than 1 percent of the state’s 113,700 mi. of roads but carry approximately 18 percent of the state’s vehicle miles.

Petri said an interstate number for 41 has not been determined but that it would logically remain 41, because I-43 is to the east and I-39 is to the west.

U.S. 41 stretches 224 mi. from Marinette in the north to Pleasant Prairie in the south in Wisconsin. The entire highway stretches 2,000 mi. from Copper Harbor in the Upper Peninsula of Michigan to Miami, Fla.