The heavily traveled section of the I-83 corridor serving the City of York has an average daily traffic count of more than 65,000 vehicles. Excessive congestion, motorist delay, and a higher-than-average crash history defined the existing condition along both the expressway and local road network. Complicating matters, Mill Creek, a high-quality waterway, meanders through the project area, flowing under I-83, Mount Rose Avenue, and multiple ramps. Erdman Anthony was selected to develop potential solutions to improve the Exit 18 (Mount Rose Avenue) interchange and complete final design of the preferred alternative.
Multiple alternatives were proposed, including a Single-Point Urban Interchange (SPUI), a diverging-diamond interchange, a compressed-diamond interchange, and several hybrid alternatives. Ultimately, one of the hybrid alternatives with a modified partial cloverleaf geometry was selected as the optimal solution. The selected alternative includes:
- reconfiguration of the interchange
- reconstruction of one mile of I-83 mainline
- widening of Mount Rose Avenue to seven lanes
- improvements to five signalized intersections
- construction of seven bridges, two box culverts, and two noise walls
- construction of an access road to an adjacent business park
When complete, this project will improve safety and performance through the interchange, improve traffic flow on local streets, and accommodate future growth.