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Clarion Curve Widening and Realignment

Gannett Fleming created a safer roadway and sidewalk, allowing easier access for the Clarion community.
  • Re-aligned Clarion Curve after construction, near Comet Food Warehouse and Dollar General - Gannett Fleming.

    Roadway realignment flattened an existing substandard curve and improved sight distance requirements.

  • A two-way left turn lane for cars - Gannett Fleming.

    The two-way left turn lane increases driveway access and alleviates rear-end crashes.

  • An ADA-compliant sidewalk with ramps at the Clarion Curve roadway intersection - Gannett Fleming.

    New ADA-compliant sidewalk with ramps, improved safety, accessibility, and mobility for residents.

  • Stormwater drainage system including storm sewers and inlets - Gannett Fleming.

    The project involved upgrading the stormwater drainage system, including new storm sewers and inlets.

  • New utility lines in front of nearby houses - Gannett Fleming.

    Extensive coordination was necessary with utility companies to relocate all of the lines in the project limits.

  • A pre-construction view of the Clarion Curve that shows a narrow roadway without a dedicated turn lane - Gannett Fleming.

    A pre-construction view of the Clarion Curve area.

Pennsylvania Department of Transportation, Engineering District 10

Heberling Associates, Inc.; The Markosky Engineering Group, Inc.; Monaloh Basin Engineers, Inc.

Clarion, Pennsylvania

Our Role
Design, Engineering, Traffic, Construction Services

0.5 miles
Construction Cost
$3.5 million
11 years
  • Wider and straighter roadway lanes with curb gutter shoulders
  • New continuous two-way left turn lane
  • New ADA-compliant sidewalk with ramps
  • New storm sewer system.

A vital gateway to the town of Clarion, Pennsylvania, state Route (SR) 68 provides key access to the county’s only hospital, Clarion University, Interstate 80 (I-80), and numerous shopping and dining locations. Section 374 of the roadway, a half-mile stretch known locally as the “Clarion Curve,” was sharp, narrow, and did not provide adequate pedestrian access. 

Beginning in 2005, Pennsylvania Department of Transportation (PennDOT) District 10 contracted with Gannett Fleming to perform studies and develop improvements for the entire 2-mile SR 68 corridor from I-80 to U.S. 322. In 2011, preliminary and final engineering was initiated on the half-mile Clarion Curve section. Now widened and realigned, the Clarion Curve features a safer roadway, a new sidewalk, improved drainage, flooding abatement, and better accessibility to the greater Clarion community.

What We Did

Existing Clarion Curve conditions created limited sight distance for vehicles on the road and exiting adjacent driveways. By flattening the curve radius and widening the road, Gannett Fleming helped to improve sight distances. A continuous two-way left turn lane also was created to enhance residential and commercial driveway access and to alleviate rear-end crashes. The final pavement design consisted of full-depth widening with an overlay of the existing pavement.

A key feature, Gannett Fleming added an Americans with Disabilities Act (ADA)-compliant sidewalk on the east side of SR 68, starting at the Comet Food Warehouse driveway and heading north. The new sidewalk provided a link to existing sidewalks, allowing pedestrians to safely walk to their downtown Clarion destination. Gannett Fleming also resolved Clarion County Conservation District drainage and stormwater concerns regarding a storm system that has experienced flooding issues. The system collects runoff from a large drainage area and eventually flows into Trout Run, approximately 200 feet east of SR 68. Gannett Fleming designed a solution to divert future stormwater runoff from this parallel storm system by upsizing the main storm trunk line to 42 inches.

Key Features

  • Maintained traffic during construction, ensuring that local businesses remained open
  • Proactively coordinated with six local utility companies to determine best underground and aerial line relocation and timeline for minimized disruptions
  • Improved drainage along SR 68, mitigating future flooding.

Awards & Recognition

  • 2016 Outstanding Highway Engineering Award, ASHE Mid-Allegheny Section

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