With less than a year before construction begins, the Fern Valley Interchange project team is sifting through techniques to expedite work while keeping businesses open and traffic on the move.
“It will be quite a trick in such a tightly-developed commercial and residential interchange area,” said ODOT Project Leader Dick Leever. “Our goal is to keep impacts to a minimum. We will quickly and efficiently build the project in stages that keep Interstate 5 and the local roadways open.”
The project team collaborated with a group of private contractors earlier this year to come up with the best construction methods. According to Leever, significant grade differences — the new roadway is designed to rise nearly eight feet above the current level at the top of the southbound I-5 off-ramp — and the close proximity of the new bridge ramps to the existing ramps are just a few of the major challenges the project faces.
The result of that collaborative meeting with contractors was a staged approach that sets aside a large area for unimpeded construction and builds temporary roadways and ramps that open up the project area for heavy construction.
“We’re proposing the project contractor builds temporary southbound on- and off-ramps in the southwest quadrant of the interchange area, funneling traffic into Phoenix via Luman Road,” Leever said. “However, staging proposals may be refined again when a contractor comes on board next year.”
The project was fully funded thanks to a $25 million investment from the 2009 Oregon Jobs and Transportation Act (JTA), a funding package based in part on increases in truck weight-mile taxes, flat fees, registration fees, road use assessment fees, and heavy vehicle trip permit fees.
“The JTA investment was great news,” said ODOT Area Manager Art Anderson. “A major transportation investment like this reflects the excellent work being accomplished in the Rogue Valley.”
Unlike former Oregon transportation bills, the JTA dedicated most of the state’s share of revenue to specific projects. The bill listed 37 projects previously approved by the Oregon Transportation Commission that must be financed by bonds.
The $73 million Fern Valley Interchange project goes to bid in April 2013.
“Between now and next spring, our staff will be meeting with the people who own, who work and who live in the affected properties around the interchange,” said ODOT Spokesman Gary Leaming. “Once we have a contractor selected, we will invite the Phoenix community to join us for a project open house.”
Leaming said his focus will be on keeping the community informed during the two-year construction schedule.
“This will be a challenging project,” Leaming said. “We’re building new roads, new ramps and new bridges. We’re widening Highway 99. Normal routes will change until the project is complete. There will be some short closures and delays.
“But we’ll do our best to minimize the impacts.”
Aesthetic features inspired by the hills and grasses — the natural colors surrounding Phoenix — are being incorporated in the final design for the new Fern Valley Interchange project.
The utilization of concrete form liners and different stains and paints presents opportunities to design a bridge with a local look instead of the drab concrete structures common when I-5 was initially built.
The project team filtered through several designs with the help of Medford landscape architect, John Galbraith, before selecting aesthetics for the Fern Valley Road bridges that span I-5 and Bear Creek at exit 24.
The Fern Valley interchange connects I-5 and Phoenix at exit 24. The interchange experiences traffic congestion through the day, but is especially severe during the morning and evening commutes. Existing and proposed development along the east side of I-5, as well as development growth within the Rogue Valley, are choking the interchange’s capacity and causing safety concerns.
The project’s design phase began in 2004. The Fern Valley Through design alternative was eliminated in 2009 because it would have an adverse impact on nearby farm land. Later, the Project Development Team unanimously supported the North Phoenix Through build alternative as part of the federally-required environmental assessment.
ODOT will construct the Fern Valley Interchange project using a crossing diamond design that provides a higher capacity to move traffic while reducing right of way needs.
Vehicles crossing the interchange move to the opposite side of the road to either enter I-5 or to cross it, reducing the number of signal cycles for traffic to clear. The Missouri Department of Transportation was the first agency in the United States to construct an interchange of this design.
The project design keeps roadways relatively untouched east of the interchange while constructing a new interchange just north of the existing one, and realigning North Phoenix Road between Home Depot and the Peterbuilt shop.