As part of the Kentucky Transportation Cabinet’s Mountain Parkway Expansion, a 45-mile transportation improvement project in Eastern Kentucky, STV provided comprehensive surveying, civil, structural and geotechnical engineering design services for a 4.6-mile mainline section of KY 9009 in western Magoffin County, extending from just west of the Cutino-Hagar Road overpass to just west of the Gifford Road overpass. The project widens the Parkway from two to four lanes with a 40-foot depressed median, improving safety, mobility and access with a more modern connection to the region.
In support of this effort, STV developed alignment alternatives to improve geometrics through the “Kernie Cut,” a 180-foot rock cut requiring intermediate and roadside ditch benching throughout the corridor. The project generated approximately 4.6 million cubic yards of rock excavation and included significant sections of side hill design.
STV evaluated five design alternatives, assessing 60, 65 and 70 mph speeds, 5% and 6% grade impacts and the feasibility of a bifurcated section. The firm developed a matrix comparison table analyzing the impact of each option, considering earthwork, rock excavation, channel changes, right-of-way takings and relocations, guiding the selection and advancement of a preferred alternative.
STV also conducted a comprehensive study to determine the optimal placement for a new grade-separated rural diamond interchange, integrating it into the revised alignment.
When the Kentucky Transportation Cabinet decided to widen the environmental footprint, STV completed a new alignment study, resulting in an estimated cost savings of over $40 million.
4.2
miles of mainline roadway
5
alt. alignments studied
$40M
estimated cost savings
