[co-authored by Lilly Jacobson]
Streets are not just conduits for moving cars and people; they have a profound impact on the neighborhoods they traverse and connect. Streets often change how people perceive their environment: they can make people feel safe or deter them from walking in a certain area; they can encourage social interaction or create deserted sidewalks; they can spur economic activity or stall neighborhood growth. Street design is not merely about aesthetics and modes of mobility—streets have the potential to affect the health and life outcomes of everyone who uses them.
Streets are the largest and, perhaps, until recently one of the most often overlooked element of the public realm. They are considered mere connectors from one place to another, but they are actually places in and of themselves. People from all backgrounds interact as they walk along sidewalks, perhaps spending even more time in these public spaces than in formally recognized areas like parks or plazas. Street design can promote social interaction through creative and inviting seating, public performance spaces, playspaces for children, or even elements as simple as street trees and benches. They foster fleeting communities that come and go such as the Poetry Slam at 16th Street and Mission outside a San Francisco BART Station. The interactions also strengthen the more traditional long-term communities built from neighborhood connections and events.
In the 1970s, Donald Appleyard, a pioneer urban designer and thinker conducted a study to determine the affects of traffic on neighborhood social interactions. He studied three streets in San Francisco that were identical except for their volumes of traffic. The study concluded that the streets with light and moderate traffic created communities that were knit closely together and fostered social ties. In contrast, the street with heavy traffic fostered an environment where social ties were one third as likely to occur. Additionally, Appleyard studied the social gathering on each of these streets and noticed that streets with light traffic were generally seen as a whole and no part of the physical space was “out of bounds.”
Both these fleeting and permanent communities create a space for the mixing of people, fostering tolerance and acceptance simply by bringing people of different backgrounds together. Tolerance is the basis for a more just and equitable society: the more people are encouraged to share public life, the more accepting they will be of differences. Streets, as conduits of daily public interaction, have an impact on the overall social health of our society.
There are some obvious wide-reaching health implications associated with street design, mainly centered on environmental elements such as pervious paving and bioswales that reduce stormwater runoff, phytoremediation plants that aid in reducing pollution from motor vehicles, and bike lanes and public transportation networks that improve safety and reduce carbon emissions. However, there are more subtle health impacts that often fly under the radar in street design dialogue. These involve perceptions of safety and, ultimately, life outcomes for community members living with poorly designed streets. Both physical and mental health are affected by perceptions of neighborhood safety, and street design plays a large role in this.
In the 1960s Jane Jacobs coined the classic term “eyes on the street” to explain the safety benefits of an active and busy street life. An archetypical example of this urban occurrence is the barber shop, typically a street-level establishment with a glass façade that helps to create an intrinsic connection between the interior space of the barber shop and the street. These establishments foster communities along the street, perpetuating these notions of “eyes on the street,” and ultimately leading to a safer environment for street users.
However, eyes on the street can affect more than how safe we feel on a sidewalk; it can affect our physical health as well. A recent study conducted by the Santa Clara County Public Health Department showed that residents who perceived crime, violence, and drug activity in their neighborhoods reported having worse physical and mental health conditions, which can be compounded by a fear of using streets to walk, exercise, and play. Increased traffic, a lack of pedestrian safety and increased pollution can cause additional health problems such as asthma and cardiovascular disease. The Santa Clara County study also found that low-income neighborhoods tend to be less walkable–the health impacts of poor street design disproportionately affect disadvantaged populations. Bad street design is a threat to public health and equity.
Finally, street design has a significant impact on the economic vitality of a neighborhood. The number of people on a street increases the number of potential customers walking along a commercial corridor. The design of a street and its attractiveness to pedestrians can encourage new business development because business owners know they will have a ready customer base. This reinforcing cycle of business activity and customers can spur the economic growth of a community, and alleviate other issues along the street, as well. In lower income neighborhoods, where economic growth might be stagnant, good street design thus has the dual effect of improving residents’ health and increasing economic opportunities in their neighborhood.
Redesign of urban areas does not have to usher in waves of gentrification; programs like the Dudley Street Neighborhood Initiative are working to help foster sustainable and economic development in low income neighborhoods in Boston. This program gathers residents, community partners and small business owners and helps them to engage and develop a cohesive community vision which they can work towards as a unified group. This effort, which advocates development without displacement, marks a paradigm shift in the trends of modern urbanization. Vibrant and successful streets will no longer be confined to neighborhoods with high-income residents, but rather, successful streets are places where development can help transform a community into a safe and livable space for all.
In our urban mental maps we shape through our experience, we organize cities into neighborhoods defined by socio-economic status, ethnicities, aesthetics and tradition. Our cities have become a series of boundaries dividing people and deterring them from connecting to the larger grid of ideas and community. But streets do not have to be bound by neighborhoods, rather they have the ability to transcend boundaries and connect people with places, providing opportunities for justice, health and economic activity. Initiatives such as re:Streets, are now pushing us to redefine our mental maps, breaking down the hard boundaries of neighborhoods and fostering the connections between them with innovative and creative street design. Ultimately, it is a revolution in how we view our streets that will help transform them into spaces everyone can thrive.
 Appleyard, Donald, M. Sue Gerson, and Mark Lintell. Livable Streets. Berkeley: U of California, 1981.
 Jacobs, Jane. The Death and Life of Great American Cities. Pelican Books: n.p., 1964.
 Santa Clara County Public Health Department, Associations between Neighborhood Conditions and Health Outcomes at Local Level. 2010. http://www.sccgov.org/sites/sccphd/en-us/Partners/Data/Documents/neighborhoods%20poster%20combined%20final.pdf
This article was co-authored by Lilly Jacobson and Marissa Reilly:
About Lillian Jacobson:
Lilly Jacobson is a Master of City Planning Candidate (2015) at Massachusetts Institute of Technology, focusing on City Design and Development. She is an Urban Design and Planning Intern at MIG in Berkeley, California and has centered her career on community engagement and social justice in urban design. Her background is in community organizing and public sector planning, and she most recently worked as the Community Planner at the Fenway Community Development Corporation in Boston. She plans to continue working in urban design and public engagement, making strides towards more just and equitable cities.