Anatomy of a sidewalk
Getting the details right makes for more pedestrians.
Most people are familiar with sidewalks, the strip of cement somewhere between the front of the building and the street. But if it is designed poorly, it will not be used. Design of the sidewalk should be part of thorough design of the street, areas next to the street and more (some call this complete streets design). The idea is to take into account enclosure aspects as well as overall urban design.
There are multiple areas within a sidewalk that have different functions and differing psychological associations that need to be taken into account. People do not like to walk up close to a building or adjacent to traffic and naturally shy away from these areas.
Let’s look at residential sidewalks first. They should be five feet in width. This is the adequate space for pedestrians to pass comfortably. If the sidewalk is against a fence or wall, add an additional foot for passing space and a shy zone. Ideally there is a planting strip (grass, plant beds, trees, etc.) of seven feet between the sidewalk and the street.
Commercial street sidewalks have several issues to deal with as they have pedestrian movements, function as gathering space and other uses. Typical commercial sidewalks should be 13 - 15 feet wide in order to accommodate four sidewalk zones:
- Frontage or loiter zone: area for retail pedestrian window shopping and outdoor seating. The loiter zone provides an area out of pedestrian walking flow for someone to stop or engage.
- Throughway zone: pedestrian walking zone that allows for unimpeded movement of pedestrians. This zone should be at least five feet wide.
- Furnishing zone: area for street furniture and pedestrian loitering. Street furniture includes lighting, landscaping, trash containers, public seating, art work and more.
- Edge of buffer zone: a “shy” zone for pedestrians to create some distance from motor traffic, parked cars and walls.
Sidewalks can also be too wide. If a sidewalk is too wide in a retail area it can appear vacant or under-used and present the problem that pedestrians may feel uncomfortable in too large of a space. Commercial sidewalks also need to take care regarding enclosure ratios. If the sidewalks will make the right-of-way appear too wide in relation to the adjacent building height then the sidewalk or entire street right-of-way may be too wide. In a commercial area, the distance from the front of a building on one side of the street to the building front on the other side of the street should be within the range of one to two times the building’s height. If sidewalks are too wide one might use street trees, artwork or banners to create a pedestrian enclosure which does not appear too wide. The location of trees or other objects should be placed so they do not to block views of retail signs, window displays, and entrances.
These design details are important for creating a space that is welcoming to pedestrians. Walkable communities are a primary preference for people looking to locate in a community. Michigan State University Extension has several training programs focusing on urban design and streets to help communities. Contact a Land Use Educator for more information on these programs.