SR 28 Highland Park Interchange Improvement Project

Pittsburgh, Pennsylvania

Michael Baker provided comprehensive engineering services to upgrade the State Route (SR) 28 Highland Park Interchange in Pittsburgh Pennsylvania. Michael Baker's services included project management, alternatives development, environmental compliance, value engineering, design, complex construction sequencing and traffic control plans, intelligent transportation systems and construction consultation. The project addressed frequent bottlenecking, traffic congestion and accidents due to the two-lane reduction at the interchange site.

This project focused on upgrading the interchange to alleviate traffic congestion, improve safety and provide a smoother driving experience. The project also addressed frequent bottlenecks and accidents at the interchange site. Before the project, rush hour speeds on SR 28 were a frustrating 15 miles per hour, with traffic jams stretching up to 1.7 miles. The addition of through lanes, acceleration and deceleration lanes and a northbound auxiliary lane has significantly improved traffic flow and reduced congestion.

The most important sustainable feature was offsetting and mitigating stormwater in the corridor to reduce flooding. A rain garden was installed within the ramp infield area to retain and reduce stormwater into the system flowing under the railroad and into the Allegheny River.

By approving 13 design exceptions to safely reduce design criteria, the project rehabilitated five bridges and four retaining walls rather than reconstructing them, thereby reducing costs and minimizing impacts to the public. The team developed over 240 special provisions as unique solutions and non-standard construction elements to reduce future maintenance along the unique and challenging corridor.

The project includes a unique 3D textural surface treatment design for the sound barrier panels, created in collaboration with a local artist. The design, inspired by the Allegheny River, adds an aesthetic element to the infrastructure.