As the most expensive highway project in Georgia’s history, the nearly $1 billion Northwest Corridor project will add nearly 30 mi. (48.2 km) of reversible toll lanes along interstates 75 and 575 through Cobb and Cherokee counties.
As the most expensive highway project in Georgia’s history, the nearly $1 billion Northwest Corridor project will add nearly 30 mi. (48.2 km) of reversible toll lanes along interstates 75 and 575 through Cobb and Cherokee counties. The managed lanes project was designed to bring relief to motorists using the corridor, which is one of the region’s most congested thoroughfares.
“The Northwest Corridor Express Lanes project (NWC) is vital to the state of Georgia because it will help reduce congestion, provide more reliable travel times and help improve air quality in a heavily traveled region,” said John D. Hancock, assistant state innovative delivery engineer. “NWC will offer both drivers and transit customers a more reliable trip time, improve traffic flow and provide travel options. When time is most valuable, drivers will have the option of choosing the express lanes to bypass congestion when they desire.
“As the Atlanta region grows in population, so do the needs of the traveling public. This project will help support Atlanta’s regional transit vision by improving transit on these key links to the integrated transit system. Depending on the length and direction of the commute, travel time savings for the NWC, compared to the No-Build Alternative for 2018, are projected to range from 5 to 43 minutes. It’s also important to note that transit buses and registered van pools will be able to travel in the lanes for no additional fee, offering their customers a more reliable trip time.”
The Northwest Corridor project aims to make transportation improvements to I-75 and I-575 in the Northwest Corridor. The proposed improvements include the addition of managed lanes on both I-75 and I-575 within the project area from Akers Mill/I-285 north to Hickory Grove Road. Access points along I-75 are proposed at I-285, Terrell Mill Road, Roswell Road, I-575, Big Shanty Road and Hickory Grove Road.
Along I-575, the proposed improvements include the addition of a managed lane system in the median between the I-75/I-575 interchange and Sixes Road. The managed lane system on I-575 could, as an option, include slip ramp access between the managed lane and the general-purpose lane systems, rather than direct access interchanges at Big Shanty Road, Shallowford Road and Dupree Road.
The Georgia Department of Transportation (GDOT) selected Northwest Express Roadbuilders, a joint venture of Hubbard Construction Company of Winter Park, Fla., Parson’s Transportation Group of Pasadena, Calif., and Archer Western Contractors of Atlanta to perform construction. Work began in October 2014, with the project slated for completion by spring 2018. The developer proposed a construction phasing plan to work in various areas of the 30-mi. corridor, but it will be completed as one project.
“Construction is beginning to gear up, and is visible throughout the entire length of the project,” said Hancock. “Significant activity can be seen right now at the Canton Road area, where a bridge over one-mile long is currently being constructed. Activity at the I-285/I-75 juncture is also increasing where motorists can see extensive work building the bridges that will connect express lane traffic to I-285. Work on five bridges and roadway drainage is currently under way in the median on I-575. Hickory Grove Road over I-75, which is a new express lane interchange, is currently being replaced.
“Unlike delivery methods for other projects, the design-build-finance delivery for the Northwest Corridor Express Lanes project involves a construction schedule that will continue to evolve as the design-builder moves through the process of optimizing all aspects of design. This project involves substantial amount of bridge work, which will constitute the bulk of construction activity throughout the life of the project.”
Construction expected in 2015 includes more than three-dozen bridges, with eight of the bridges set for completion this year. Another 22 bridges will be under construction by the end of 2015. In addition, 63 retaining walls and 34 retaining walls are scheduled for completion this year.
Roadwork includes drainage, embankment, subgrade, base and paving. In the I-75/I-285 interchange, roadwork will continue throughout 2015, as the interchange bridge work continues. I-75 southbound will be permanently shifted to the new pavement and bridge over Terrill Mill Road, from Delk Road down to Windy Hill Road.
The I-75 Express Lanes will be under construction along the west side of the I-75 right-of-way, from the I-285 interchange, north to the I-75/I-575 split.
Construction will continue north up I-75, and the alignment shifts to the median of I-75 just north of the I-75/I-575 split. There will be construction in the I-75 median from the I-75/I-575 split, north to about 1/2 mile north of Hickory Grove Road. There also will be construction in the I-575 median, and will occur from the split, north to Sixes Road in Cherokee County. Sound barrier construction is scheduled to start in fall 2015. Drainage work, clearing and grubbing, paving and pavement marking will be ongoing. Concurrent construction activities will continue throughout the design-build phase until spring 2018.
Throughout the project, GDOT anticipates the use of 16 cranes for substructure and superstructure work, installation of pre-cast beams and steel girders. The cranes include boom truck cranes, crawler cranes and mobile cranes. Other equipment includes dozers, excavators, loaders, motorgraders and compactors for dirt and pipe work, pile hammers and a drill rig for bridge work and pavers and sweepers for roadway work.
Some of the main materials that will be used include 1 million cu. yds. (764,554 cu m) of excavated dirt, 140,000 linear ft. (42,672 m) of drainage pipe, 280,000 linear ft. (85,344 m) of barrier wall, 1.4 million sq. ft. (130,064 sq m) of sound barrier, 100 retaining walls, 315,000 sq. yds. (263,380 sq m) of concrete paving, 350,000 tons (317,514 t) of asphalt paving, 17,300 cu. yds. (13, 226 cu m) of sub-structure concrete and 92,000 linear ft. (28,041 m) of pre-cast beams.
Approximately 81,437 cu. yds. (62,263 cu m) of dirt has been excavated and moved within the project limits. Crews have completed 40 percent of the clearing for the project, while 6,286 cu. yds. (4,805 cu m) of concrete have been poured to date. Regarding bridge work, 24 pedestals have been completed with footing, column and cap, which amounts to approximately 16 percent of constructed pedestals for the entire project. Also, 73 bridge beams have been set so far, with the entire project consisting of 40 bridges. In addition, workers have installed approximately 50,000 linear ft. (15,240 m) of temporary barrier wall within the project limits.
“This project has been in the planning stages for approximately 14 years, with the biggest obstacles in the form of funding strategy and environmental commitments,” said Hancock. “It’s been a long road to bring GDOT’s first P3 project from concept to contract. In 2003, the state law passed to allow unsolicited public private initiatives proposals. The state law then evolved in 2005 to allow for both solicited and unsolicited proposals, and changed again in 2009, which required only solicited proposals. Fast track to 2012, the Northwest Corridor project was redeployed as a P3 Design-Build-Finance (DBF), and the DBF agreement was finally executed in November 2013.
“Some of the biggest challenges include educating the public on the managed lanes concept, and minimizing traffic impacts to existing traffic during construction on a project with a length of approximately 30 miles. Throughout construction of the NWC project, GDOT will provide regular construction and traffic updates on its Web site, Georgia Navigator 511, social media posts, media announcements, newsletters and community outreach events.
“GDOT ensures that traffic impacts to motorists are minimized as much as possible by scheduling night-time lane closures and providing advanced notification of lane, shoulder and ramp closures through a variety of communications outlets.”
Most of the work for this project will occur off the existing roadway and in the median. Lane closures will occur during off-peak traffic hours.
“GDOT has developed a traffic and construction weekly update that is emailed to the public, and encourages anyone interested in the project to sign-up for these notifications, said Hancock. “In addition, GDOT is working closely with our partners, including city and county governments, community improvement districts, transit agencies and businesses and community groups to ensure that construction updates are readily available and widely communicated.”
Federal and state standards for traffic control during construction are being implemented.
“All phases of construction activity for the Northwest Corridor Express Lanes are guided by an established health and safety program for the project,” said Hancock. “This program is based on a sincere desire to eliminate personal injuries, occupational injuries or illnesses and damage to equipment and property, as well as to protect the public whenever and wherever the public is exposed to, in contact with, or is affected by project construction. All traffic control message boards and signage are utilized in accordance with MUTCD specifications and per approved construction plans. Safety crews are continually on the job site to inspect and monitor work zones and traffic barricades for potential safety hazards and compliance with safety policies.”
In addition, all project employees are required to attend a four-hour safety training session upon hiring that covers environmental compliance, work site specific safety rules, and Occupational Safety & Health Administration standards. Ongoing trade-specific trainings take place on a regular basis and include fall protection, excavation, confined space and work in high-traffic area trainings.
When the project opens to the public in 2018, the NWC will provide a new mobility choice to a corridor that routinely carries as many as 230,000 vehicles each day.
“Alerting the public about construction impacts is one of the primary goals for the project team,” said Hancock. “The majority of public inquiries received are related to the project’s design and construction schedule, tolling policies and maintenance of the new lanes. The functionality of the facility and access to the lanes for safety personnel are also topics of public interest, as this project will introduce the first reversible express lanes system in Georgia.”
Funding for the project includes $265.8 million from the state transportation improvement program, which consists of federal and state funds, along with $275 million from a Federal Transportation Infrastructure Finance and Innovation Act loan, $300 million in state motor fuel funds and $59.8 million financing provided by the project’s private sector partner, NWER, to be paid back by GDOT at the completion of the project, which is 10 percent of the project’s design-build cost.
“GDOT anticipates drivers and transit customers who use the Northwest Corridor Express lanes will be able to bypass traffic congestion and experience a more reliable trip time. There will be increased travel options between general purpose and express lanes, reliable trip times and expanded transit options with transit buses and registered van pools allowed to travel in the express lanes for free.”
At the Northwest Corridor groundbreaking ceremony, Gov. Nathan Deal told reporters, “The Northwest Corridor project is a critical addition to Georgia’s interstate highway system, providing a reprieve for congestion on two of the state’s busiest thoroughfares. This project will create new commute options for motorists and boost our state’s economic development efforts, as maintaining a strong transportation system is a key component to attracting new business to the state.”
The project corridor is northwest of downtown Atlanta. The study area encompasses the suburban cities of Marietta, Kennesaw and Acworth and several unincorporated communities in Cobb and Cherokee counties. The area is home to a substantial share of the metro region’s population as well as major corporations, several business centers, two large regional shopping malls and Dobbins Air Force Base.
The Northwest Corridor is home to a substantial portion of the region’s population. It also is one of the most economically important areas, containing several of the region’s major activity and employment centers, including Midtown Atlanta, Cumberland Galleria, Marietta and Town Center. Rapid growth in population and employment in the Northwest Corridor is expected to continue through 2035. Officials have said unless improvements are made to accommodate this growth, congestion will likely get worse.