The Rockleigh Historic District in Bergen County is a remarkable testament to New Jersey's Colonial past. Organized around a core network of three roads dating to the eighteenth century, it is characterized by a scattered collection of eighteenth- and nineteenth-century farmhouses and outbuildings set within a moderately sloped terrain enhanced by towering trees and rock-filled watercourses. As a means of ensuring the preservation of the district's historic roads, a resolution by the New Jersey Historic Sites Council stipulated the completion of design guidelines by a qualified architectural historian, landscape architect and traffic engineer. Spearheading this effort, GDPC served as the project manager and principle investigator on the Rockleigh Historic District Historic Roadway Design Guidelines, which entailed a historical evaluation of these roads' significance, an inventory of their character-defining features, and recommendations to balance their preservation with future traffic and safety needs.