His plans of Greek cities were characterised by order and regularity in contrast to the more intricacy and confusion common to cities of that period, even Athens. He is seen as the originator of the idea that a town plan might formally embody and clarify a rational social order.
According to Aristotle (in Politics), Hippodamos was a pioneer of urban planning and he devised an ideal city to be inhabited by 10,000 men (free male citizens), while the overall population including the correspondent women, children and slaves would reach 50,000 people. He studied the functional problems of cities and linked them to the state administration system. As a result he divided the citizens into three classess (soldiers, artisans and 'husbandmen'), with the land also divided into three (sacred, public and private).
He also evidently had a reputation as a lover of attention. According to Aristotle's description in Politics, "Some people thought he carried things too far, indeed, with his long hair, expensive ornaments, and the same cheap warm clothing worn winter and summer."
For Pericles he planned the arrangement of the harbour-town Peiraeus at Athens in the middle of the fifth century BC. When the Athenians founded Thurii in Italy in 443 BC he accompanied the colony as architect - although he was not actually an architect in the sense of a building designer. He is credited with, in 408 BC, the building of the new city of Rhodes, however as he was involved in 479 BC with helping the reconstruction of Miletus he would have been very old when this project took place.
His “diamond” grid plans that he invented (and later named after him) consisted of series of broad, straight streets, cutting one another at forty-five and one hundred thirty-five degree angles. In Miletus we can find the prototype plan of Hippodamos. What is most impressive in his plan is wide central area, which was kept unsettled according to his macro-scale urban prediction/estimation and in time evolved to the “agora”, the center of both the city and the society.
The “Urban Planning Study for Peiraeus” (451 BC), which is considered to be a work of Hippodamus, formed the planning standards of that era and was used in many cities of the classical epoch. According to this study, neighborhoods of 240 square meter blocks were constructed were small groups of 2-floor houses were built. The houses were lined up with walls separating them while the main facets were towards the south. The same study uses polynomial formulas for the plumping infrastructure manufacture.
From Hippodamus came the earliest notions of patent law. Hippodamus proposed that society should reward those individuals who create things useful for society. Aristotle criticized the practical utilitarian approach of Hippodamus and implicated the inherent tension in rewarding individuals for doing good; i.e. that by rewarding individuals for doing good, the individuals will do good for the reward over the benefit of the state. The state could actually suffer because of the allure of individual rewards, since individuals may propose notions that weaken the state. Aristotle essentially foreshadowed the inherent tension between private rewards for social benefits--the potential diversion between individual and societal interests.
Hippodamus does not seem to have been involved in politics, but several writings attributed to him dealt with issues of the state, including «Περί Πολιτείας», «Περί Ευδαιμονίας», «Πυθαγορίζουσαι Θεωρίαι» (titles difficult to translate into English.)
Robert Patrick Merges & John Fitzgerald Duffy, Patent Law and Policy: Cases and Materials (3d ed. 2002).