In Fairbanks, Alaska’s second largest city, the Gaffney Road/Airport Way/Richardson Highway/Steese Expressway intersection (GARS) was notorious.
The intersection sees 26,000 vehicles a day, and the congestion, especially during peak hours, caused delays. As traffic volumes increased, so did the frequency of accidents, many of which were rear-end and angle collisions caused by poor signal performance and the high demand for left turns.
Recognizing the urgent need for a solution, the Alaska Department of Transportation & Public Facilities (DOT&PF) turned to HDR Engineering for a solution. The goal was clear: improve safety and traffic flow while avoiding the high costs and long delays associated with a grade-separated interchange.
The project team set out to create something truly unique—something that had never been tried before in Alaska, according to the project team.
The team merged two advanced traffic control elements: the Continuous Flow Intersection (CFI) and the Median U-Turn (MUT) design. Both elements were already known for their ability to improve traffic flow by eliminating left turns at the heart of the intersection, but they had never been combined in such an integrated way.
The result was a reimagined intersection that was efficient and cost-effective. The new design saved an impressive $30 million and enabled construction to begin 6 to 10 years ahead of the original schedule.
The CFI-MUT hybrid improved travel times and reduced evening commute delays from 7 minutes to just 1.5 minutes. Queue lengths were also significantly reduced, easing congestion and lowering the potential for rear-end crashes. Safety was enhanced as well, with a 32% reduction in all crashes and a 20% decrease in serious or fatal accidents.
But the success of the project didn’t just come from its clever design. Technology played an essential role. In the early phases, HDR employed microsimulation models to analyze traffic patterns, optimize signal coordination and evaluate the potential impact of different design options. These models allowed the team to make data-driven decisions that ensured the final design was effective and tailored to the needs of Fairbanks drivers, who often had to contend with Alaska's unique driving conditions.
HDR hosted virtual open houses and created high-resolution videos that allowed community members to visualize the new traffic patterns from the driver’s perspective. This approach educated the public and gathered valuable feedback.
But construction wasn’t without its challenges. In addition to the usual obstacles for Fairbanks projects, like coordinating with local military and managing snowplowing operations, signal coordination for the CFI-MUT required custom controllers to handle the complex phasing, which was unlike anything the city had used before. But with collaboration and ingenuity, the team navigated these hurdles successfully.
By the time the new intersection opened, it was clear that the project had not only solved a long-standing traffic problem but had done so in a way that was more efficient, cost-effective and safer for everyone involved. The GARS intersection, once a bottleneck, now demonstrates how thoughtful engineering and bold thinking can achieve smoother commutes and save lives.
Project: Gaffney Rd/Airport Way/Richardson Hwy/Steese Expy Int.
Location: Fairbanks, Alaska
Owners: Alaska Department of Transportation & Public Facilities (DOT&PF)
Designer: HDR Engineering, Inc. (HDR)
Contractor: HC Contractors
Cost: $2.5 million design/$19 million construction
Length: 1 mile
