The $72 million Fern Valley Interchange project is headed into the home stretch, with roughly four months left, following more than two years of highway construction in Phoenix at the Interstate 5 Exit 24.
Work currently underway includes the opening of the permanent northbound off-ramp, widening and base paving on Oregon 99 and Bolz Road, and final striping. Construction work still to come includes final paving on the west side of the interchange, new traffic signals and the opening of the Bear Creek Bridge. The project is scheduled for completion in September.
“The project is really starting to come together now as we enter the summer,” said ODOT Project Manager Tim Fletcher.
Fletcher said the last month was a busy one with I-5 paved in the project area and the new southbound on-ramp opened, following a five-day closure to connect the temporary ramp with the permanent one.
“After the ramp opening, we put down permanent stripes and repainted the temporary stripes we first added last February during the interchange’s partial opening,” said Fletcher. “The temporary paint fades fast.”
The application of temporary paint allowed for additional adjustments as traffic adapted to the Diverging Diamond design. Fletcher cited one example where yield bars were moved to improve sight distance for southbound traffic taking the off-ramp to travel east of Phoenix.
The next, and final, ramp to complete is the permanent northbound off-ramp, which is scheduled for a July opening.
“Work on the northbound off-ramp is harder than it was on the southbound on-ramp,” said ODOT Project Information Specialist Gary Leaming. “We need to move more material because of the old bridge approach. And a water detention pond must be built.”
The Bear Creek Bridge is also slated to open in July. Once traffic shifts over to the new structure, work will focus on adding sidewalks to the north side.
“The bridge will open but still be an active work zone,” said Leaming.
The Bear Creek Greenway has been in a detour since the beginning of the project. Bridge replacement necessitated a rapid flashing beacon to warn motorists of Greenway users crossing the road. According to Fletcher, there’s still work left to connect the permanent Greenway ramps to the new bridge and build a connection beneath it.
“ODOT has made it a priority to keep the Bear Creek Greenway connected during the construction project,” said Jackson County Greenway Coordinator Jenna Stanke. “The Greenway has about 400 daily users.”
New Street Names
Once the project is complete, different names will appear on some project area roadways. ODOT met with Phoenix officials and emergency service representatives several years ago to coordinate the changes.
• North Phoenix Road will carry through the overpass to the west side of I-5 and terminate at the Oregon 99 signal across from Ray’s Market.
• Fern Valley Road will appear only on the east side of I-5, terminating at a cul-de-sac joined by Pear Tree Lane.
• Grove Road will replace South Phoenix Road in the southeast area of the project, extending across Fern Valley Road through the traffic signal near Home Depot before reaching a dead end behind the Lazy Boy Furniture store.
Diverging Diamond Design
The Fern Valley Interchange features Oregon’s first Diverging Diamond design, which reduced ODOT’s right of way needs for construction.
“The Diverging Diamond design was developed specifically with Phoenix in mind,” said Leaming. “The objective was to reduce the project footprint. That reduces the project’s impact on surrounding businesses and reduces right of way costs. The design also provides better traffic capacity and safety for motorists.
“To enter I-5 or cross over it, drivers move to the opposite side of the bridge, which reduces the number of signal phases a driver needs to clear.”
‘Show Me State’ Inspiration
The Missouri Department of Transportation was the first in the United States to construct an interchange with this diamond design. Several DOTs across the nation have since adopted the design.
The ODOT project team traveled to Missouri in 2010 to meet with Project Manager Don Saiko and see the new design first hand. Located on Interstate 44 at the intersection with Missouri Highway 13 in Springfield, the new design moves traffic efficiently and safely through a previously-congested intersection in a major commercial area.
The new design is important to freight haulers. Time spent sitting in a bottleneck is money lost.
ODOT produced a 3-D traffic simulation video to illustrate how the new interchange design would work.
“It really helps people see how to navigate a diverging diamond interchange,” said Leaming. “The 3-D traffic simulation video is still available online at the project website.”
Problem, Process, Solution
The Fern Valley Interchange connects I-5 and Phoenix at Exit 24. The interchange experienced traffic congestion through the day, but was much worse 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, reduced the interchange’s capacity and caused 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. The Project Development Team later unanimously supported the North Phoenix Through build alternative as part of the federally required environmental assessment.
A $25 million investment from the 2009 Oregon Jobs and Transportation Act — a funding package based in part on increases in truck weight-mile flat fees, registration fees, road use assessment fees, and heavy vehicle trip permit fees — was the last piece of the Fern Valley Interchange project’s funding puzzle.
That same year, the Phoenix Planning Commission and Phoenix City Council approved an Interchange Area Management Plan for I-5 Exit 24. The IAMP is a requirement of the Oregon Transportation Commission, which sets policy for ODOT.
In 2012, the ODOT project team collaborated with a consortium of private contractors to develop construction methods best suited for the challenges ahead of this project, such as the close proximity of the new bridge ramps to the existing ramps.
Aesthetic features inspired by the natural colors surrounding Phoenix, the hills and grasses, are incorporated in the Fern Valley Interchange project. The use of concrete form liners and different stains and paints presented opportunities to design a bridge with a local look instead of the drab concrete structures commonly built when I-5 was first constructed.
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.
Work Zone Safety
People benefit from many safety features in the Fern Valley Interchange project’s work zone, including TripCheck traffic cameras, the Rogue Valley’s Incident Response vehicle, transverse rumble strips and a reduced speed limit to 50 mph.
The Oregon State Police patrols the work zone. Traffic fines double in work zones, even when there are no workers present. TripCheck cameras were installed to help keep an eye on traffic in the work zone.
“Adding TripCheck cameras to the project provides drivers with timely information to avoid congestion during construction,” said Leaming.
ODOT maintains a temporary construction office within The Shoppes at Exit 24 to serve as a base of operations for the project inspectors. The public is welcome to stop by the office for more information.
How Do You Drive a Diverging Diamond Interchange?
The Diverging Diamond Interchange is a different driving experience. The DDI moves traffic more safely and efficiently. Do your homework now. Learn how to drive the DDI.
Project Page: http://goo.gl/9qIVIU
Watch the project video, which shows you how to drive the new Fern Valley interchange at I-5 Exit 24. https://m.youtube.com/watch?v=b01H54zLV0s
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