Arial view of a vertical six-lane roadway with commercial buildings along both sides.

Lehigh Valley SR 0100 Roadway Reconstruction

Our Client’s Challenge

State Route 100 (SR 0100) in Upper Macungie Township, Pennsylvania, was a small road with little traffic in the 1930s. It has grown to become an integral part of the transportation network for Lehigh County’s industrial and commercial businesses, with average daily traffic of over 36,000 vehicles (21% of which are trucks). Over several decades, the road was pieced together, widened, and required a complete reconstruction.

Our Solution

The roadway engineering project for a SR 0100 section included four high-demand intersections, an I-78 interchange, and an at-grade railroad crossing with Norfolk Southern.

The Pennsylvania Department of Transportation (PennDOT) District 5-0 turned to Gannett Fleming for final design transportation engineering services for a full-depth roadway reconstruction project of 1.36 miles of SR 0100 between Industrial Boulevard and SR 1002 (Main Street/Tilghman Street.) The design called for a four- and six-lane roadway while maintaining the existing curb-to-curb width, existing drainage outfall elevations, and traffic flow during construction.

The concept development and design process included evaluating existing pavement of various depths and materials, including concrete overlay sections and full-depth asphalt sections. The team analyzed several alternatives in design. A bonded concrete overlay on asphalt (BCOA) was originally selected in preliminary design due to its ability to accommodate heavy truck traffic. However, in final design, BCOA was replaced with a full depth asphalt pavement, which included a stone matrix asphalt (SMA) wearing course. SMA is specially designed to resist rutting from large truck traffic.

The underground utilities through the SR 0100 project include water services, communications, and sanitary sewer. An existing water main’s elevation fluctuated and meandered through several sections of the existing drainage. SR 0100 existing drainage networks conveyed flow offsite and outside the project limits, which required maintenance of all outfalls and tie-in elevations. The proposed storm sewer network design involved numerous iterations, including a deeper pavement section, multiple utility conflicts, and the requirement to maintain existing outfall elevations.

Project complexity also impacted traffic control. The reconstruction required lane reductions while staying within the existing curb lines. The team implemented a multi-segmented and staged approach, which offered fewer delays and a shorter construction duration for motorists, residents, and businesses along SR 0100.

The final traffic control plan consisted of:

  • Five segments.
  • 20 stages.
  • 16 minor and township road detours.
  • Railroad preemption coordination.
  • 42 temporary signal plans.

The team reduced existing SR 0100 four-phase traffic signals to two- or three- phases during construction using minor street approach closures and local road detours, eliminating the associated yellow and all-red times, thereby increasing the amount of SR 0100 green time.

Key Features

  • Intersection improvements.
  • Full depth asphalt pavement replacement.
  • Curb and gutter replacement.
  • Upgraded traffic signal equipment.
  • ADA ramp improvements for pedestrian access.
  • Underground utility relocation.
  • New cantilever sign structure.


  • Reconstructed pavement which is rut resistant and accommodates heavy truck traffic.
  • New pavement drainage for safe and efficient travel.
  • Minimal disruption to the traveling public and industrial businesses.
  • Improved drainage enhances environmental sustainability.

Awards & Recognition

  • American Society of Highway Engineers – East Penn Chapter, 2023, Project of the Year
  • American Society of Civil Engineers Lehigh Valley, 2022, Outstanding Civil Engineering Achievement


Pennsylvania Department of Transportation (PennDOT) District 5-0


Upper Macungie Township, Pa.


Final Design Engineering Services

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