Why invest $350 million to upgrade 13 miles of highway in Hamilton County, Indiana? Anyone who traveled that section of U.S. 31 during rush hour can easily answer that question.

"This area experienced exponential growth in the last couple decades," said Nathan Riggs, Public Information Director for the Indiana Department of Transportation (INDOT) East Central District. "By getting rid of traffic signals and adding interchange ramps, we're making traffic more free-flowing to reduce congestion and improve safety." The new configuration also increases capacity for travel and commerce on the highway that stretches from Michigan to Alabama.

The New U.S. 31 Hamilton County project spanned five years, upgrading the existing highway to federal freeway standards by reconstructing U.S. 31 and changing traditional intersections into various types of grade-separated freeway interchanges, with roundabouts designed to accommodate trucks and high-volume traffic in many of the ramp systems. The work stretched from I-465 at Indiana's Marion-Hamilton County line through the cities of Carmel and Westfield to Indiana State Road 38.

Combined with previously completed U.S. 31 work to the north, INDOT removed 32 stoplights between Indianapolis and South Bend, Indiana, saving drivers 30 minutes of travel time.

The project was the first in the nation to use federal transportation legislation that allows up to 90 percent federal funding for critical freight projects, instead of the 80 percent maximum for non-interstate routes. The balance of funding came from former Governor Mitch Daniels' original Major Moves program with revenue from the Indiana Toll Road lease.

Packaging to Cut Three Years

INDOT first considered bidding 11contractsone for each of the new interchanges. "We anticipated construction with that process to last through 2018," Riggs said.

To speed up bidding and construction time, "We tried to do one big bid," Riggs added. However, "The amount of time contractors were looking at involved a lot of risk; taking on a project that would span multiple years created some uncertainties with costs." 

INDOT ultimately decided to break the project into five major contracts (see "Five Pieces of the Puzzle" sidebar). A few smaller contracts covered right-of-way clearing, utilities, and other tasks. 

"Consolidating the contracts helped expedite construction," Riggs said. "Now we're hoping to get everything open to traffic by the end of 2015. We were able to shave significant time just by how we packaged and bid the contracts." 

Minimizing Impact

The first contract broke ground in April 2011 at the State Road 38 interchange, the north terminus of the project. Not wanting to impact Westfield's 40-acre MacGregor Park and Nature Preserve, INDOT opted for a folded diamond interchange. "The park took out 25 percent of the space we had to work with, so one of the ramps was folded into a loop inside one of the other three quadrants," Riggs explained.

Throughout the corridor, "We minimized construction's impact and remained sensitive to each location, whether it was parks, cemeteries, homes, or businesses," Riggs said. "Elements like MSE walls instead of slopes helped reduce the footprint along the corridor."

Indianapolis-based Milestone Contractors, L.P., submitted the lowest bid of six contractors for this part of the project, coming in 20 percent below the original estimated cost.

Maintaining Business

The next contract moved further south to construct a more efficient ramp system connecting U.S. 31, 146th Street, and Keystone Parkway. "There's been a lot of commercial development in that area so we took great care to minimize the impactnot only with the actual construction but also realizing that a lot of the access to these existing businesses would permanently change," Riggs said. 

To communicate the changes, INDOT conducted extensive outreach, including open houses before construction and at least once a year until all the contracts were awarded. "We had formal presentations and map displays, but the majority of time was just having people availableINDOT, our design consultant, and the contractors," Riggs explained. "It was pretty informal; I think that makes people more comfortable than standing up in front of a crowd in a public hearing. We tried to make it easy for everyone to get the information they wanted." 

Throughout construction, contractors utilized lane shifts instead of road closures whenever possible. "With the existing businesses and neighborhoods in the area, it was imperative to maintain access," Riggs said.

In fact, when INDOT bid this contract, they asked contractors to compete on price as well as how quickly bridges reopened to traffic. Walsh Construction of Crown Point, Indiana, submitted the lowest and best bid among three contractors, reducing the Keystone Parkway closures to 90 days southbound and 80 days northbound. 

Connecting the Dots 

The next two contracts "connected the dots between 146th Street and State Road 38," Riggs said. The two contracts in Westfield were bid separately but both won by Rieth-Riley Construction of Goshen, Indiana. In the first contract, Rieth-Riley's bid was the lowest among five contractors and nearly $5 million below engineers' cost estimates to build a variety of interchanges.

At 146th Street, Rieth-Riley constructed a split diamond interchange "stretched out to include the commercial area of Greyhound Pass on either side of U.S. 31," Riggs said   

The interchange at 161st Street was designed as a "dog's bone" or "double teardrop" roundabout. "The ramps depart U.S. 31 and elevate traffic," Riggs said. "Essentially it's two roundaboutsone on either side, with a bridge in between to connect the two. Each roundabout accommodates ramp traffic as well as 161st Street traffic, and U.S 31 flows underneath the bridge."

INDOT also awarded Rieth-Riley the adjacent contract for 4 miles to the north. That work included two U.S. 31 overpass bridges, a roundabout interchange, and a single-point urban interchange that replaced the intersection at State Road 32. "All the ramps go down and cross at an X at a single point in the middle of that interchange," Riggs explained. "Left turns go in front of each other so you eliminate conflicts and traffic back-ups."

Switching for Efficiency 

The last contract, awarded to a joint venture of E&B Paving, Inc., of Anderson, Indiana, and Gradex of Indianapolis, covered the south terminus of the project from I-465 to just south of 146th Street. "It's the longest distance and greatest cost for a single contract on the corridor and involves the largest number of interchanges and bridges," Riggs said.

In addition to U.S 31 interchange improvements at I-465, the work included four new roundabout interchanges. Last year INDOT closed asection of U.S. 31 to expedite construction.

The original plan called for construction of the other half of the contract first and the closure this year. However, "After we got into conversations with the project team, we realized we had more potential on the northern half, with more utilities and right-of-way already cleared, so we decided to switch and implement the closure one year earlier," Riggs said. 

In addition to achieving free-flowing traffic sooner, the altered schedule shortened the closure from the original 10-month forecast to eight months and improved work zone safety during construction of new bridges.

Communication and More Communication

The entire project required extensive coordination. To help avoid issues, Chad Nierman, INDOT Area Engineer, oversaw all the contracts. "Having that regular coordination kept everybody on the same page," Riggs said.

For instance, in order to minimize inconvenience to motorists, "If one contractor needed a lane restriction for a certain activity and it was near another contract where they also needed a restriction, we looked at what made the greater sense in achieving everyone's goals over the long-term," he added. "Sometimes the restrictions couldn't happen at the same time; other times we just needed to coordinate with our contractors and subcontractors."

INDOT also worked closely with Hamilton County and the cities of Carmel and Westfield, who had their own local construction projects underway. "We planned around each other to make sure we all got our work done in a timely manner, without conflicting closures or restrictions that prevented people from getting where they needed to go."

 After four years of construction, the project remains on schedule to complete all the interchanges by year-end. "We expect some construction to go into 2016likely the area underneath I-465 where the freeway ends and U.S. 31 transitions into Meridian Streetbut the goal is to have free-flowing traffic north of I-465 before the end of 2015," Riggs said.