- The new design will improve mobility at the interchange, facilitating a safer transition between highways for drivers
- The project will improve 10.5 miles of SR 400 and I-285 highways in Atlanta
This past week, North Perimeter Contractors – the lead contractor on the Transform 285/400 project in Atlanta, Georgia – opened the SR 400 Southbound to Interstate 285 Eastbound flyover ramp to traffic. The new design will significantly improve mobility at the interchange as it shifts from a “clover-leaf” design to a flyover ramp, facilitating a safer transition between highways for drivers.
Known as “Bridge 21,” the 285/400 flyover is one of 33 major structures to be built as part of the reconstruction project that will improve 10.5 miles of SR 400 and I-285, as well as add new flyover ramps, new collector-distributor lanes and other facilities to aid east-west travel along I-285 and north-south travel along SR 400.
Building a new bridge structure can be one of the most complex components in infrastructure development, particularly with structures like Bridge 21, which has a completely new footprint (ingress and egress) from the prior bridge and a soaring, 80-foot-tall apex. The cap alone at the tallest point is holding up a series of 200-foot-long steel beams, each of which weighs over 400,000 pounds.
Beyond the bridge’s design and planning and field work – including ground work prep, demolition of existing structures, materials delivery and coordination, and rebuild – tremendous work was done behind the scenes. Project and safety teams met weekly and, in collaboration with Georgia Department of Transportation, held regular briefings internally and with key external stakeholders, including emergency responders and business and neighborhood groups. Due to COVID-19, many meetings had to be reconfigured – either spatially or via video conference – to allow for social distancing.
The North Perimeter Contractors project team hosted a drive-through “thank you” luncheon for the project team prior to the opening. Public Relations Manager Annalysce Baker also chronicled the ceremonial “first drive across the bridge,” before opening the bridge to the public on the morning commute on October 5.