The recent clearing of trees around the Interstate 40 interchange at Aviation Parkway is a prelude to a reconstruction project that will begin as soon as the first week of April.
The results will include a new loop exit ramp to carry westbound I-40 drivers onto southbound Aviation Parkway. That will mean the elimination of the left-hand turn that those drivers now must make onto Aviation, which will improve the flow of traffic, according to N.C. Department of Transportation engineers.
The engineers say traffic at times already exceeds the capacity of the current interchange, which was built in 1969. Aviation Parkway handles about 28,000 cars and trucks a day at I-40, and that number is expected to grow to nearly 38,000 a day in the next 20 years, according to NCDOT.
In its current design, all traffic exiting westbound I-40 uses the same ramp; drivers going north on Aviation Parkway to Raleigh-Durham International Airport take a single free-flowing lane to go right, while southbound Aviation traffic waits for a green light to turn left.
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With the new design, southbound traffic will go under the Aviation Parkway bridge and loop around onto the southbound side of the road. RDU-bound traffic will have two exit lanes instead of one, but they'll now be met by a traffic light at the top of the ramp. The rest of the interchange will remain the same, except that the ramp onto westbound I-40 will be moved northward to make room for the new looping exit ramp.
Another change: The merge lane onto westbound I-40 will be extended a half mile to the Airport Boulevard exit, to give drivers more room to get in and out traffic.
The project is expected to cost $21.5 million and take until September 2020 to complete. Part of the replacement bridge over I-40 will be built adjacent to the existing one in phases, allowing contractors to keep all four lanes of Aviation Parkway open during construction.
The overhaul of Aviation Parkway will still be underway when work begins in late 2019 on reconfiguring and rebuilding the Airport Boulevard interchange.
The NCDOT is still weighing two options for redesigning the Airport Boulevard interchange: a partial-cloverleaf similar to the new Aviation Parkway pattern, and a relatively new kind of design called a diverging diamond. Both options aim to relieve traffic in part by eliminating left-hand turns by vehicles coming off the interstate.
The new bridges at Aviation Parkway and Airport Boulevard will be longer, to accommodate more lanes on I-40 should local transportation planners and the state ever want to widen it. The bridges will be long enough for two additional lanes on either side of the highway, which would make I-40 a total of 12 lanes wide.