Not all cities have the same street patterns, but the waffle or “gridiron” arrangement is one of the most common in the United States, having been developed in the Colonial era with various intelligent plans to make use of space, explained in Chapter 2 of Contemporary Urban Planning. However, not all cities from that time had grids and there are reasons for that, which often give hints as to the purpose of the city itself. Into the 19th and 20th Centuries, many cities expanded and continued to adhere to the gridiron plans, which makes sense in certain ways but not in some others, and one who were planning a new urban area today would need to weigh the pros and cons.
General Oglethorpe’s idea which he implemented in Savannah seems logical, having several “wards” each consisting of a square that is a few blocks across centered around an open public space. It allowed the city to expand if necessary by simply adding more wards. Also, the use of open areas at the center of each ward makes public assembly and commerce convenient, although not for the entire city. William Penn’s implementation in Philadelphia worked to a similar extent. It’s reasonable that New York and Boston both had “spaghetti bowls” of streets, for which there could be many explanations including the fact that they were on irregularly shaped land masses, or the terrain which may work better with staggered streets. Streets at angles could also work better since it allows more people to walk “as the crow flies.” Most cities in Europe had this layout that continues to exist in their old sections, which of course today is not suitable for motor vehicles but is easy for pedestrians given the number of direct routes.
However, with the introduction of public transport systems, most notably streetcars, a gridded street pattern must have proven less effective given that cities developed large centers, often with department stores, theaters, and other points of interest that hailed from the entire municipality. If transit lines were to converge downtown, the vehicles would need to take serpentine paths. Today, many grid-iron cities (e.g. Milwaukee, Miami) have bus routes each assigned to a particular street with linear paths, thus there are many “crosstown” lines which do not serve the central area, and passengers wishing to travel diagonally must do transfers. Although it was not intended, the overlaid state-named avenues in Washington, D.C., allow for the benefit of “spider web” transit systems, as does the fan-shaped pattern in New Orleans which was simply a matter of the city’s shape in between bodies of water.
Once automobiles became the primary method of transport, grid-irons became logical once again, and can be found in many car-centered cities, most notably in Los Angeles; in essence, it has been derived from Oglethorpe’s plan since there are large squares bordered by major commercial avenues/boulevards encompassing many square blocks that are primarily residential. It is much easier to take a route involving 90-degree turns in a private vehicle than on a public. As urban planners contemplate the best street patterns for new development, it may be wise not to have a strict grid if it was to be friendly to pedestrians and mass transit, but instead to have a “hub-and-spoke” system like Paris, where there are central nodes (a convenient place for transit stations to be) and streets radiating from it, even though a grid may make house numbering easier and people are less likely to lose their sense of direction.