DOT: More traffic likely means four lanes of I-90/39 in Janesville
JANESVILLE Due to increasing traffic counts, Interstate 90/39 through Janesville will look much different in nine years.
The state's Department of Transportation is moving ahead with plans to expand the Interstate from two lanes in each direction to four from Avalon Road to Highway 26 on Janesville's northeast side.
Up until about two months ago, the department was planning for an expansion to three lanes in each direction, which is still the plan for the entire Interstate expansion project that runs from the Illinois state line to the Beltline in Madison.
The additional lanes in Janesville will eat up existing median, require noise barriers through the segment's residential stretch and require a creative design to tie together nearby interchanges at Highway 14 and Highway 26.
The additional lane also will also increase the cost of the entire 45-mile project, which in February was estimated at $715 million.
Earlier this month, the state's Transportation Projects Commission learned the cost had increased to $835 million because of design refinements and inflation.
That $835 million is in 2012 dollars. Construction isn't expected to start until 2015, and by the time the project is finished in 2021, transportation officials have said the total cost likely will be more than $1 billion.
"Things have changed, and the numbers right now put the Janesville stretch very close to needing a fourth lane," said John Vesperman, the transportation department's project chief. "We have better sets of numbers, and they are consistently getting higher."
Vesperman, other transportation officials and consultants were at the Turtle Town Hall on Tuesday for a public information session on the project's south segment, which runs from the Illinois state line to County O just south of Janesville.
The project's central segment runs from County O to the Rock/Dane County line, while the northern segment stretch to the Beltline.
According to 2010 traffic counts, an average of 50,000 vehicles a day travel the Interstate in Rock County, with 35 percent of that truck traffic.
Traffic—particularly in the Janesville area—is expected to increase to 90,000 to 100,000 vehicles a day by 2040, a time period that would encompass the 20-year design life of the project, Vesperman said.
Because federal highway dollars are expected to pay for about 25 percent of the project, federal officials have a say in the design, and they have recommended that the fourth lanes be added in Janesville.
"We want to build it and then stay out of there until 2040 or beyond," Vesperman said. "We don't want to build it and then have to come back in and make improvements for something that we know is going to be needed."
Adding the fourth lane will be a challenge in the city of Janesville, which is bordered on both sides of the Interstate by homes and businesses, Vesperman said.
"We're going to build it from the middle out," he said, noting that the northbound and southbound lanes would be separated by concrete barriers.
In addition, the segment from just north of Racine Street to just south of Highway 14 would be lined on both sides with noise barriers because of the high concentration of houses along the Interstate.
In the business district to the north, Vesperman said the Highway 14 and Highway 26 interchanges likely would be reconstructed with connecting ramps because they are so close to one another.
Vesperman said his department and its consultants are only about one-third of the way into their design of the overall project.
Specific details, including right-of-way acquisitions, interchange and overpass designs and alternate routes still need to be determined.
"There's a lot that we just don't know yet," Vesperman said.
Some details, however, did emerge Tuesday about the southern segment, which will be three lanes in each direction over the 12 miles between the state line and County O:
-- The department is considering three different interchange designs for the Interstate's intersection with Interstate 43 and Highway 81 at Beloit.
-- The interchange at County S will remain much as it is now, a diamond design with stop signs. The department, however, will review driveway access to nearby business and possibly add frontage roads.
-- The Highway 11/Avalon Road interchange would be reconstructed from a diamond/stop sign configuration to a diamond with either stoplights or a roundabout.
-- Overpasses at Creek, Hart and Woodman roads will be lengthened and built with better sightlines. Where practical, bicycle and pedestrian lanes will be added in the shoulders.
-- The segment will include an Intelligent Transportation System that features cameras to monitor traffic, electronic signboards to alert motorists of potential delays and traffic data collection devices to measure travel times.