Final Design Engineering For SR 6220, Section C10

Orth-Rodgers & Associates, Inc. (ORA) prepared construction plans for a nine-mile section of Interstate 99 in north central Pennsylvania. When completed, I-99 will extend from I-70/76, the Pennsylvania Turnpike, near Bedford, Pennsylvania to I-80, near Bellefonte, Pennsylvania. I-99 also connects the railroad and industrial city of Altoona to State College, home of Pennsylvania State University and a center of high tech research. ORA was responsible for the section of I-99 that extends from Bald Eagle, about two miles north of Tyrone to a gradeseparated crossing of existing US Route 220, approximately one mile south of Port Matilda. This was a complex project involving the full spectrum of highway design activities. Key components of the construction plans included the establishment of final line, grade and typical section; roadway cross sections; design of the pavement; interchange design; maintenance and protection of traffic during construction on the existing highway network; contour grading and drainage design; stormwater management design; landscaping and roadside beautification; utility engineering; pavement marking and signing plans; erosion and sediment pollution control plans; and Plans Specifications & Estimate (PS&E) packages. The firm is also responsible for the design of four new bridges at the grade-separated crossings at the Bald Eagle Interchange and across PA Route 350. The highway project was broken into three major construction contracts: Grading Contract, Structures Contract, and Paving Contract. The construction cost for the combined contracts was approximately $140 million.

In preparing the final design plans, ORA addressed the special environmental commitments made in the Final Environmental Impact Statement for the project. One unique design feature involved the provision of separate stormwater management facilities for “roadway runoff” and “clean runoff”. Roadway runoff contains roadway deicing chemicals and debris from traffic, and clean runoff is stormwater originating from areas beyond the pavement. Other unique features that ORA designed included facilities for the re-infiltration of intercepted ground water by proposed cut slopes, provisions for wildlife corridor crossings, and hazardous spill containment facilities.

The firm was also assigned corridor-wide responsibilities. ORA developed signing plans for the entire I-99 corridor from the Bedford Interchange of the Pennsylvania Turnpike in Bedford County to the proposed Interchange with I-80 in Centre County to ensure conformance with the I-99 designation. In addition, ORA is developing Intelligent Transportation Systems (ITS) Plans for the 40-mile section of proposed I-99 from Bald Eagle to the I-80 interchange. The estimated construction cost for the ITS facilities is $20 million.