The San Francisco Chronicle reported this month that the City, while considered one of the most walkable City’s in the nation, also has one of the highest rates of pedestrian deaths. The article discussed mentions potential causes, including low car ownership, high pedestrian and transit user populations, wide streets, one way streets, and proximity to freeway ramps. One thing not mentioned in the article as a potential cause is the City’s uniform street grid plan. Much of the City’s street plan was imposed on the landscape without regard to topography. Additionally, the City blocks are relatively small (e.g., 275 x 412.5 feet) compared to many other cities. (For a comparison, see the illustration to the right. ) These facts combine to create a high number of intersections, steep and straight sections of road, and many one way streets resulting in fast cars approaching pedestrians crossing at intersections. Uniform grid street plans also have other negative effects. They are generally more costly to maintain than discontinuous or organic street patterns due the higher number of intersections. They also have greater ecological impacts because their inherent high street and intersection frequency produce large areas of impermeable surfaces comprised of the street pavement and the sidewalks. On the other hand, their benefits include fire and safety access, traffic efficiency, view corridor preservation, and pedestrian mobility/access. The benefits and detriments of uniform street grid plans vs. other plans or non-planned development is a broad topic that will revisited often in UrbDeZine.
About Bill Adams
Bill Adams is the founder and chief editor of UrbDeZine. He is also a partner in the San Diego law firm of Norton, Moore, & Adams, LLP. He has been involved with land use and urban renewal for nearly 25 years, both as a professional and as a personal passion. He currently sits on the boards or committees of ,The Public Interest Advocacy Collaborative, San Diego Historic Streetcars, The Food and Beverage Association of San Diego County, and the Heal the Gash Committee (reconnecting communities divided by freeways).