JOBSITE INNOVATIONS |
BY BRANDON NOEL
IF YOU BUILD IT, THEY WILL COME Photos Provided by Superior Construction
Superior Construction’s unique approach on a $135 million project, creates more volume for Nashville’s busy airport
T
he Nashville International Airport (BNA) is one of the busiest in the country, and in 2021, the city was ranked1 fastest growing in the United States, economically. This boom in financial growth has lots of collateral impacts, both directly and indirectly. The original roadways leading into the airport, first constructed in the 1980s, are, and have been for some time, no longer capable of sustaining and adequately serving the traffic demands it now faces. This, in part, lead to the I-40/Donelson Pike relocation project. The airport's current loop road currently services the constant stream of arrivals and departures heading into
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the main terminal entrance. This is also the access used by taxis and rideshare services, so, it isn't difficult to see why it has become so congested. The new Donelson Pike relocation project — spearheaded by Superior Construction and the Tennessee Department of Transportation (TDOT) — is designed to realign the Donelson Pike interchange to the east. This allows the Metropolitan Nashville Airport Authority (MNAA) to relocate BNA's loop road to provide a badly needed increase to the airport's circulation capacity, as well as added real estate for more car parking. BIG RELOCATIONS, UNIQUE DESIGNS To achieve this, Superior crews broke ground in July on the relocation of the Donelson Pike interchange at Interstate 40 southeast of downtown Nashville. The plan is to update the junction to a diverging diamond interchange (DDI) design. The DDI is a subset of diamond interchange in which the opposing directions
of travel on the non-freeway road cross each other on either side of the interchange so that traffic crossing the freeway on the overpass or underpass is operating on the opposite driving side from that which is customary for the jurisdiction2. There are many advantages to this unique type of solution: • Two-phase signals with short cycle lengths, significantly reducing delay • Reduced horizontal curvature reduces the risk of off-road crashes • Increases the capacity of turning movements to and from ramps • Potentially reduces the number of lanes on the crossroad, minimizing space consumption • Reduces the number of conflict points, thus theoretically improving safety • Increases the capacity of an existing overpass or underpass by removing the need for turn lanes • Costs significantly less than a normal interchange This isn’t Superior’s first DDI. "We will leverage our experience on other
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10/18/22 11:38 AM