The Twelve Tables, compiled around 450 BCE as Rome's earliest codified body of law, included provisions on the physical layout of roads, specifying a width of about 8 Roman feet on straight stretches and 16 feet at curves, along with mandatory clear space between buildings. The rules placed obligations on adjoining owners to maintain the way. They translated customary practice into written, enforceable standards. The dimensions reflected the needs of carts passing one another.
They represent the earliest codified street-width and building-setback standards in the Western legal tradition. The principle that public law could fix the dimensions of streets and the spacing of buildings became a durable instrument of urban order carried through Roman and later European practice.