As part of the ongoing planning and engineering efforts for the Section 1 reconstruction of West Grand Avenue, GSG performed a comprehensive non-destructive geophysical survey within the project limits, extending from North Ogden Avenue to North Morgan Avenue in Chicago, Illinois. The primary objective of this survey was to support the design and construction planning process by identifying potential subsurface structures—specifically, the presence and extent of vaulted sidewalks—without the need for intrusive excavation. To achieve this, Ground Penetrating Radar (GPR) technology was employed.