Grid street plan

Collection of historic towns lattice frames. Manuel de Sola Morales, 1977

The grid plan, grid street plan or gridiron plan is a type of city plan in which streets run at right angles to each other, forming a grid. Many of the earliest cities in the United States, such as Boston, did not start with a grid system. However, even in the pre-revolutionary days some cities saw the benefits of such a layout. New Haven Colony, one of the earliest colonies in America, was designed with a tiny 9-square grid at its founding in 1638. On a grander scale, Philadelphia was designed on a rectilinear street grid in 1682; one of the first cities in North America to use a grid system. Arguably the most famous grid plan in history is the plan for New York City formulated in the Commissioners’ Plan of 1811, a visionary proposal by the state legislature of New York for the development of most of Manhattan above Houston Street. An exception to the typical, uniform grid is the plan of Savannah, GA (1733). It is a composite, cellular city block consisting of four large corner blocks, four small blocks in between and a public square in the centre. Its cellular structure includes all the primary land uses of a neighborhood and has for that reason been called fractal. Its street configuration presages contemporary traffic calming techniques applied to uniform grids where certain selected streets become discontinuous or narrow thus discouraging through traffic.