The plan of Philadelphia, one of the oldest planned cities in the U. S. was designed by Thomas Holme in 1682 under orders of William Penn, the governor. Its features are regular gridiron street pattern and detached houses surrounded by gardens, orchards, or fields to realize “green country town.” Today, however, the blocks are filled with row houses instead of detached houses and there are various and very comfortable streets formed through subdivision of the planned large blocks. The purpose of this study is to describe the structure and the diversity of the streets themselves and the space made by three planes, street itself and façades of row houses on both sides.
The analysis of street patterns on Insurance Map of Philadelphia, vol. 1, 2, Sanborn Map Co., New York, 1916 shows that the originally planned streets were mostly realized and preserved and the inner-block street patterns of all blocks were different from each other already at that time. And by the observation in our field survey done three times from 2013 through 2015, the inner-block streets are spatially articulated by visual closure of those ends and have some kind of hierarchy including the planned streets.
The four blocks were selected to be surveyed at the fieldwork. Each block is located in the districts of Society Hill, Washington Square West, and Rittenhouse Square. The streets in and by these blocks are classified into four types: Type A planned street (15m width), type B running through a block and connecting A with A, and type C (6m width) connecting A with B. Type B includes type B1 (15m width) and B2 (7-9m width). The results of classification by scale (street width), sectional proportion (street width by row house height, W/H), and spatial articulation are as follows: Type A is wide in scale, large in W/H, and not articulated. Type B1 is wide, large, and articulated. Type B2 is narrow, medium, and articulated. Type C is narrow, small, and articulated. And the condition of traffic, one of the main functions of street corresponds to the types. In addition, these characteristics just follow the street types and do not differ by districts.
The distinctive features of the row houses that form streets are exterior wall, podium, stoop, sidewalk, roadway, front yard, dry area, basement opening, and flowerbed. The stoops and the basement openings are at the corners of exterior wall and sidewalk, and making small and cozy space. On the other hand, the front yards, the dry areas, and the flowerbeds are the elements to strengthen the continuity of streets. The examination of these features and their materials indicates that these are almost same in each block regardless of streets types but vary by districts. The differences of scale and sectional proportion by their street types and those of distinctive features and their materials by districts give two-dimensional diversity to the streets in Philadelphia.
On most streets the exterior walls and the sidewalks are strongly connected and form L-shaped space. The street type A is divided by roadway and its space is considered as the combination of two L-shaped spaces. On the street type B1, roadway is almost for pedestrians and L-shaped spaces on both sides are joined and should be called L+U-shaped spaces. And the street types B2 and C form U-shaped spaces.
This work was supported by JSPS KAKENHI Grant Number 25420681.
