Design and Geospatial Services

THE PROJECT
PennDOT District 8-0 sought to improve traffic flow along 2.6 miles of Interstate 81 near its interchange with Interstate 83, a heavily traveled corridor carrying 84,000 vehicles per day. Due to surrounding development and other constraints, the widening had to make optimal use of existing PennDOT
right-of-way.

Erdman Anthony was selected to provide design and surveying and mapping services for the project.

FEATURES/SOLUTIONS
The project’s features included:

•    An auxiliary lane added in both directions to connect the ramps at the two interchanges, relieving
     congestion during morning and evening rush hours

•    Concrete roadway slab repair, joint repair, pavement repairs as specified by the PennDOT
      maintenance unit, and an overlay of the entire project area

•    Improved stormwater management facilities that used linear components such as vegetated swales
     and infiltration trenches to minimize the need for detention facilities and associated right-of-way

•    Signage updates and new pavement markings

Erdman Anthony’s geospatial team used mobile LIDAR to safely gather accurate geospatial data due to the high traffic volumes. Outside the roadway, the team used Real Time Kinematic GPS and more conventional survey techniques to map existing drainage, noise walls, and other features.

IMPACTS
The design and completed project have relieved traffic congestion, improved infrastructure conditions, and improved safety. A three-stage traffic control plan requiring temporary roadway design effectively maintained traffic during construction.

Because this project is part of a larger interstate improvement initiative, final design was completed under an expedited schedule, with construction plans, specifications, and estimates delivered just seven months after Erdman Anthony received design field view approval from PennDOT.