The S.R. 220 (Interstate 99) projects sought to address growing traffic concerns of the Centre County region of central Pennsylvania. The State College area was experiencing rapid growth which was forecasted to continue for at least the next 20 years. This growth coupled with other regional increases in population led to an increase in traffic on S.R. 220, resulting in congestion and safety concerns.
The Approach
The 7.2-mile section of the U.S. 220 portion of the I-99 corridor project included both roadway on new alignment and reconstruction/widening of portions of the existing four-lane expressway at the northern terminus. As part of the project, McCormick Taylor developed an intricate interchange design complete with collector-distributor roadways to meet traffic demand, interstate design criteria and local municipality concerns. Restricted by the existing topography and the need to maintain existing mainline and local road traffic during construction, detailed E&S and traffic control plans were required to construct this intricate interchange.
Preliminary and final designs were completed for two culvert structures and nine bridge structures. The bridge structures ranged from single-span to six-span structures and consisted of skewed structures on curved horizontal alignments, and structures over roadways and streams. Foundations included spread footings, bearing piles, and friction piles. The two culvert structures consisted of one new concrete box culvert and one concrete culvert extension. Additionally, URS, our subconsultant, designed two bridges (over railroad) and two box culverts (wildlife crossing under S.R. 6202).
McCormick Taylor also handled signing plans, utility relocation coordination and design, design of bikeway/pedestrian facilities, preparation of final right-of-way plans and consultation services during construction.
The Result
McCormick Taylor completed the final design and preparation of final plans, specifications and estimates for the U.S. 220 portion of the I-99 corridor stretching from east of Port Matilda, Pennsylvania to the Mt. Nittany Expressway on the northwest side of State College, Pennsylvania.
Upon completion of this project and adjacent construction sections to the south and east, the new continuous four-lane facility, will extend from the current terminus of I-99 near Tyrone, PA to Interstate 80 near Bellefonte, PA. When completed, the new roadway will provide a regional, limited access facility serving both regional and local traffic in the State College area of Centre County.
In 2003, McCormick Taylor received a Diamond Award for Engineering Excellence from the American Council of Engineering Companies of Pennsylvania (ACEC/PA) for our design of the S.R. 6220, Section B12 project which included the Scotia Road/Mt. Nittany Expressway Interchange.
