Is there anything as commonplace in our lives that we have less familiarity with than the basic components of our streets? Certainly, there is a lively history of engagement with urban planning, from famous rebuilds of cities, such as of Paris in the 19th century or the early 20th century design ideal of curvy residential streets that was part of the Garden City movement (think of some Edina neighborhoods, for example) or the New Urbanist push for neighborhoods with sidewalks and a mix of development.
We’ve also had epic fights to preserve neighborhoods from highway projects. On a national basis, Jane Jacobs’ classic work, “The Death and Life of Great American Cities,”came out of one such fight in New York City. Locally, Interstate 94 plowed through African American communities in Saint Paul and Minneapolis, forging a long-lasting anger and suspicion of transportation projects.
We think of our streets as “ours,” especially the ones that pass in front of where we live, or the ones we walk or bicycle or drive daily to get places. But do we have an ordinary, everyday sense of how transportation planners view the swaths of real estate called streets that fall between one property line and another? We probably know far more about how houses are built (roof, walls, foundations, even soffit, fascia) or where food comes from (whether it’s our garden or the freezer case at the market) than we do the basic components of our streets.
For example, have you ever considered the components of a sidewalk? There are four parts, according to the Federal Highway Administration, which in turn credits Portland, Ore., for creating the following zones in order to improve the experience of people walking, including people with disabilities: curb, planter or furniture, pedestrian and frontage.
The curb zone (6 inches to 2 feet wide) is pretty basic — the part right next to the roadway. It’s no surprise that curbs are raised to keep excess water and vehicles off the sidewalk. People who are visually impaired rely on the curb to mark the border between the sidewalk and moving traffic. Also called the transition zone, this is the space where people get in and out of cars, if on-street parking exists.
Next in from the curb is what’s called the planter or furniture zone, an area (2 to 10 feet wide) for various necessary stuff: utility poles, fire hydrants, signs, trees, bus shelters, street lights, benches, and (important in our climate) plowed snow. Whether paved or planted with trees, this zone is meant to keep all the obstructions out of the pedestrian zone. It also provides a buffer between the walkway and moving traffic.
The pedestrian zone is the part of the sidewalk corridor where people actually walk. It has to be at least 4 feet wide and has to meet the standards of the Americans with Disabilities Act (ADA). It should be smooth and flat, without fancy pavers or decorative elements (put these in the furniture or frontage zones), and should provide as direct a route as possible. A width of 5 feet is fine for a neighborhood sidewalk, but more is needed in business districts or transit corridors where there’s a higher flow of people walking.
Farthest from traffic and closest to the property line, the frontage zone (from 2 to 6 feet wide) provides a buffer between the person walking and buildings, storefronts, walls, or fences. In a commercial corridor, it provides space for doors to open, shopkeepers to place a sandwich board or, if wide enough, restaurants to put some tables and chairs.
“The width of the sidewalk corridor is one of the most significant factors in determining the type of pedestrian experience that the sidewalk provides,” according to the FHWA. The total sidewalk should be from 8.5 to 12 feet wide. When less is available, first priority goes to creating a clear walkway for people with disabilities, meaning that other uses may have to be restricted. There are ways to grab more space, such as adding bump-outs at intersections or bus stops. (See the “Urban Street Design Guide” published by the National Association of City Transportation Officials for a wealth of ideas.)
Thanks to my former co-worker Tony Hull, now of Toole Design Group, for first clueing me into the zones — and giving me some background for this piece. Hopefully, as he says, understanding the sidewalk’s zones will be a step in developing a common language that planners and residents can use to create more vibrant, interesting, and walkable streets.
Hilary Reeves is communications director for Transit for Livable Communities.