Interstate 81 at Interstate 83 Widening

Erdman Anthony routinely provides surveying services in support of our own engineering design projects. This project was initiated to widen approximately three miles of existing interstate to accommodate the capacity of two merging interstate highways.

The proposed design was severely constrained by existing conditions, and the widening had to occur without taking additional right-of-way or replacing existing bridges. These constraints made accurate mapping essential. In addition, the project limits experienced one of the highest traffic volumes in the metropolitan Harrisburg area, so there were serious safety concerns about surveying the site.

To address the surveying needs, Erdman Anthony utilized mobile LIDAR laser scanning within the travel lanes. This provided complete and accurate coverage of the roadway, signage, and bridges. Perhaps more importantly, it significantly reduced the exposure time of survey crews to moving traffic. Although targeting was required along the shoulders, the survey crews could be protected by attenuator trucks, without the need to close lanes or stop traffic.

Outside the roadway, Erdman Anthony used Real Time Kinematic and more conventional survey techniques to map existing drainage, noise walls, and other features.

Erdman Anthony performed the surveys in accordance with PennDOT’s DM-3 and Pub 122M and provided deliverables in requested Microstation and InRoads formats.

Project Details


Harrisburg / Dauphin County, PA


Pennsylvania Dept. of Transportation



Project Contact

Bryan Merritt, PSM/LS
  • Bryan Merritt, PSM/LS
  • 561-753-9723 x 6017
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