The Georgia Department of Transportation (GDOT) is making headway on its Major Mobility Investment Program (MMIP), an ambitious initiative to reduce congestion and advance mobility in key regions of the state. This $11 billion bundle of megaprojects – made possible by the state’s Transportation Funding Act of 2015 – is among the largest programs of its size and scope in the nation.

The MMIP, introduced in 2016, encompasses a diverse range of infrastructure upgrades, including interchange reconstruction, interstate widening, bridge modernization, express lanes, and commercial vehicle lanes projects. At present, it is divided into 17 individual construction packages that are scheduled to be open to traffic between 2020 and 2032. Once all work is completed, transportation experts say there will be a 5 percent annual reduction in delays and travel-time savings.

To accelerate project schedules and encourage innovation, the multifaceted program is being delivered using only alternative contracting methods – a first for GDOT, according to Darryl VanMeter, who leads the transportation agency’s Office of Innovative Delivery as Assistant P3 Division Director/State Innovative Delivery Administrator.

“We could not deliver a historic program, such as the MMIP, without using alternative delivery methods. It would be impossible; we would be building forever. Instead, we are addressing these challenges head-on with innovative solutions,” he commented further in the Spring 2019 edition of Transportation Point, an industry resource published by HNTB Corporation.

“We are setting an accelerated delivery schedule for these major projects that will create additional capacity for faster travel, more efficient freight transport, and improved operations in critical corridors,” adds GDOT Commissioner Russell McMurry. “The resulting benefits to Georgians will be significant in the form of new capacity, job creation, growth in the state’s economy, and continued development of innovative travel options.”

The initial MMIP projects to break ground are advertised as I-85 Widening, Phase 1 and I-85 Widening, Phase 2. These separate, yet complementary, projects are taking place along a 24-mile stretch of highway between I-985 and U.S. 129 in Gwinnett, Barrow, and Jackson counties, which are located in the bustling metro Atlanta region. The scope of work consists of expanding I-85 from two to three lanes (adding a total of 47 new lane miles), replacing multiple outdated bridges, and upgrading signage, striping, and guardrail along the corridor.

The estimated price tag for both projects is nearly $210 million. GDOT awarded both contracts to C.W. Matthews Contracting Co., Inc. (C.W. Matthews), which is utilizing a design-build approach to accelerate project delivery. The Marietta-based general contractor has participated in numerous other high-profile projects in its home state of Georgia, including the $360 million Fifth Runway Embankment Project at Hartsfield-Atlanta International Airport, the $147 million I-85/SR 316 Interchange Project in Gwinnett County, and the $226 million I-75 South Metro Express Lanes Project in Henry and Clayton counties.

I-85 Widening, Phase 1 has been under construction since July 2018 and is on target to achieve substantial completion this summer. GDOT used a best-value, variable-scope procurement approach to incentivize competition and provide the most lane miles of widening within a maximum budget. The $114.8 million proposal submitted by prime contractor C.W. Matthews included a bid for an additional 4 miles of capacity beyond the base scope.

Along with C.W. Matthews, major players on the project team include lead engineering firm Infrastructure Consulting & Engineering, PLLC and HNTB, which is serving as program manager. Other key firms participating as subconsultants/subcontractors to the design-build team include Michael Baker International, Arcadis U.S., Inc., Willmer Engineering, Inc., Long Engineering, Inc., and KCI Technologies, Inc.

In this phase, construction activities span roughly 10 miles between I-985 in Gwinnett County to just north of SR 53 in Jackson County, a high-traffic area that averages 118,850 vehicles each day. The project is expanding I-85 from two to three lanes by adding one general-purpose lane in each direction – northbound and southbound – of the existing grass median.

“Because we’re doing all widening in the median, no right of way acquisition was required,” says Marlo Clowers, P3 Project Manager for GDOT’s Office of Innovative Delivery. “The lane widths are our typical 12-foot lanes, with paved 12-foot shoulders on the inside and outside of the highway.” A concrete slipform median barrier constructed by Blount-Sanford Contracting Company, Inc. will divide northbound and southbound traffic.

As is GDOT’s standard practice today, an open-graded friction course (OGFC) mix is being applied to the roadway surface to improve tire friction and surface drainage and extend the life of the pavement. In addition to the estimated 421,350 tons of asphalt required for the highway expansion, the project also calls for 181,000 cubic yards of earthwork, 11,800 linear feet of drainage pipe, and four mechanically stabilized earth (MSE) retaining walls.

To mitigate noise impacts caused by the added general purpose lanes, eight sound barriers are also included in the project. “To enhance the appearance of the corridor, the sound walls are designed with an ashlar finish,” Clowers says. The total area of the precast concrete structures, fabricated by Oldcastle Infrastructure, Inc., is over 478,000 square feet.

Clowers adds, “We’re also installing intelligent transportation system (ITS) technology throughout the corridor. This includes closed-circuit television (CCTV) cameras, vehicle detection and monitoring devices, ramp meters, and changeable message signs. All of this information will feed back to GDOT’s traffic management center and be part of the NaviGAtor system, which provides drivers with real-time travel data.” Electrical contractor Brooks-Berry-Haynie & Associates, Inc. is spearheading the ITS installation process.

This phase also calls for the replacement of two mainline bridges over Mulberry River as well as three functionally obsolete overpass bridges at Spout Springs Road, Jesse Cronic Road, and Flowery Branch Road.

“All of these bridges are over 50 years old,” Clowers explains. “Though still structurally sound, they did not meet current GDOT design standards.”

The original northbound/southbound bridges spanning Mulberry River were 228 feet long, each with two 12-foot lanes and narrow shoulders on both sides. In contrast, the replacement bridges are 198 feet long and each one contains three 12-foot lanes with wider 12-foot shoulders. The modern design also features concrete bents, prestressed concrete beams, and cast-in-place concrete bridge decks.

According to Heather Bartlett, Senior Program Manager at HNTB, a staged construction approach was used to minimize negative impacts to the traveling public. Crews started by demolishing the inside 12 feet of each existing bridge, then built the first portions of the replacement structures inside of the 73-foot gap that was created as a result of the demolition. Next, traffic was shifted to the new bridges to allow for complete demolition of the original structures and to finish construction of the replacement bridges. The timeline for these activities occurred between December 2018 and April 2020.

The final design scheme of the Mulberry River bridges serves to minimize environmental impacts, Bartlett notes further. “With the existing bridges, the columns were located in the river, with four equal spans. However, the redesign eliminated the need to place columns in the middle of the river. The new structures each have a longer span that is 162 1/2 feet long and a shorter span that is 35 1/2 feet long,” she says.

For the three overpass structures, crews had to tear down and rebuild them one at a time, per contract specifications. “Those bridges were required to be completed in 180 days, or six months,” Bartlett adds. “We started with Spout Springs in January 2019 and detoured traffic while the bridge was demolished and rebuilt. The new bridge opened to traffic in July 2019. Then we moved to the Jesse Cronic, which was completed in December 2019.”

At the time of reporting, crews were on track to complete the new overpass at Flowery Branch in July 2020. The new structure will act as a gateway of sorts into Gwinnett County for I-85 southbound traffic and include aesthetic enhancements such as decorative parapet walls featuring the county’s logo and other signage, LED lighting, and pedestrian sidewalks, which are being paid for by the county.

“This effort represents GDOT’s commitment to being context sensitive,” Clowers notes. “The aim is to provide something that’s not only functional, but also attractive to the community.”

Project officials anticipate that major project activities during Phase 1 will wrap up this summer. The northbound and southbound lanes from Hamilton Mill Road to SR 211 already opened to traffic in October 2019 (approximately two months ahead of schedule) and the ones from SR 211 to SR 53 opened in June 2020 (approximately one month ahead of schedule). All remaining punch-list items are scheduled to be finished by final acceptance in October 2020.

With the end in sight for Phase 1, the next stage of expanding I-85 will soon be underway. Final design of Phase 2 is anticipated to occur later this year, with construction slated to start in 2021. These corridor improvements, valued at $94.6 million, will pick up where Phase 1 left off by widening I-85 from two to three lanes in both directions from SR 53 to just north of U.S. 129. Additional work includes replacing one overpass bridge and six mainline bridges along I-85. Substantial completion is expected in 2023.

The two I-85 widening projects, combined with other MMIP projects, will ultimately add 300-plus new lane miles to Georgia’s roadway network – a much-needed resource to help keep pace with future infrastructure demands. Nation-leading population growth, among other factors, will place greater strain on an already aging transportation system. By 2040, the state is forecast to have a population of approximately 15.6 million compared to around 10.7 million in 2010, according to a Cambridge Systematics study published in 2016.

The MMIP’s plethora of benefits extend to both drivers and the community – from safer road trips and more reliable travel times to reduced fleet costs and less environmental impact. A few projected outcomes include a 13 percent reduction in traffic fatalities and serious injuries, a 44 percent travel-time reduction for transit vehicles, and a 13 percent reduction in vehicle emissions (NOx, VOC, PM2.5) due to less congestion and faster travel times. Furthermore, overall travel times are expected to decrease 15 percent by 2040, resulting in an annual travel-time savings of $3.28 billion.

Clowers concludes, “GDOT’s emphasis on the MMIP demonstrates its commitment to expanding statewide mobility. Advancing this network of projects will provide more reliable trip times, enhance safety, and improve freight movement throughout the state.”

The Georgia Department of Transportation’s Major Mobility Investment Program (MMIP) aims to create additional capacity, improve freight movement, provide operational improvements and efficiencies, enhance safety, offer more reliable trip times, and decrease travel times. The MMIP represents a total investment of $11 billion and encompasses a host of large, complex projects in key regions across the state, which are noted below.

• I-16/I-95
• I-285/I-20 West
• I-285/I-20 East

• I-285 Eastside
• I-285 Top End
• I-285 Westside
• SR 400

• I-85 Phase 1 (I-985 to SR 53)
• I-85 Phase 2 (SR 53 to U.S. 129)
• I-16 (I-95 to I-516)

• I-75 (SR 155 to I-475/I-75 interchange)

• I-285 Westbound Ramp Extension
• I-285/Peachtree Industrial Blvd. Interchange Improvements
• I-285 Westside Railroad Crossings Bridge Widenings
• I-285 Westside Bridge Replacements
• I-285 Eastside Bridge Replacements
• I-285 Westbound Auxiliary Lane Extension