This monograph provides a systematic metrological and quantitative analysis of Roman urban planning, evaluating forty newly founded Italian colonies and municipalities to reconstruct original foundational designs. Challenging modern historiographical tendencies that view ancient centers through isolated, heterogeneous paradigms, the research demonstrates how standardized planimetric-functional templates directly reflected central authority mechanisms from Rome. By analyzing perimeter boundaries, insula modules, street networks, and forum spatial percentages across both synchronic structural frameworks and diachronic architectural evolutions, the investigation establishes a comprehensive classification of foundational layout rules. Despite severe multi-layered post-ancient site transformations, rigorous comparative metrology reveals consistent grid-based modular formulas that adapted systematically to regional hydrographic and topobiographical conditions. Ultimately, these findings illuminate the fundamental balance between centralized administrative design and environmental adaptability, offering essential criteria for identifying original urban frameworks throughout the conquest of the Italian peninsula.