Monday, April 15, 2013

NYC: Urban Design As A Catalyst For Safety

New York, not surprisingly, is leading the way in another design facet—urban design that promotes safety.  Several organizations, including the John Hopkins Center for Injury Research and Policy, the New York City Department of Health and Mental Hygiene, the New York City Department of Transportation, and many others formed a partnership and published a collection of guidelines.  The report, titled “Active Design Supplement: Promoting Safety,” is a thorough study focused on urban design strategies that improve safety. 

The report pulls from existing research and best practices, illustrating design guidelines for increasing safety while promoting a healthy lifestyle and a high livability.  Eighteen urban scale and nine building scale strategies were pinpointed.

Planning practices included highlight how the design of streets, public spaces, and neighborhoods can alleviate the risk of injury and decrease the number of transportation-related injuries and deaths.  Additionally, these practices increase the use of active transportation.

A few examples published in the report include: Complete Streets, street calming, and pedestrian refuge islands. 

Complete Streets provide safe, convenient, and accessibility for all users.  Generally, Complete Streets design elements are applied as new construction or as retrofits to an existing street.  While there is no “one-size-fits all” approach, an evaluation of Complete Streets showed that, “Roads with a refuge island, signalized intersections, curbs and sidewalks can reduce vehicle speed and increase pedestrian safety.” 

Columbus Circle in NYC after the implementation of the Green Light for Midtown project, credit: NYC DOT 
Street calming improves the quality of the experience for pedestrians and bicyclists by slowing vehicle speeds and/or reducing vehicle traffic.  Studies reveal that speed humps, road narrowing, and four-way stop intersections have been noted to decrease road traffic crashes, especially pedestrian and bicycle collisions.

Street calming feature in Claremont section of Bronx using speed humps and gateway neckdowns, credit: NYC DOT
Pedestrian refuge islands are best instituted in the center of the roadway, separating opposing lanes of traffic.  While this strategy is not suitable for all roadways, it is a proven strategy to improve pedestrian safety for wide streets and aging pedestrians.

Pedestrian refuge island on Monroe Street in Chicago, credit: Steven Vance
These three strategies are just a few of many highlighted.  I encourage you to read the report to learn more about how urban design can promote safety. 

Thank you to Ben Chaney for editing this post.


Pollack, Keshia M., PhD, MPH, Maryanne M. Bailey, MPH, CPH, Andrea C. Gielen, ScD, ScM, and M. Elaine Auld, MPH, MCHES. Active Design Supplement: Promoting Safety. Rep. Ed. Karen K. Lee, MD, MHSc, FRCPC and Sarah Wolf, MPH, RD. 2012. Web. 13 Apr. 2013.

Additional reading: 
NYC Transportation Commissioner Janette Sadik Khan- 

First NYC 20 mph Zone to Slow Cars-



  1. I'm surprised that a city as pedestrian-oriented New York doesn't already have 20 mph zones.

    I know the conventional wisdom (backed up by studies) is that signs don't slow people down; they soon stop noticing them and just drive the speed the physical design of the road indicates. But judging from the pictures you included, it looks like New York is putting more effort into making the driver aware of the pedestrian crossing / 20 mph zone than any other I've seen in cities out west. Good luck to the city, I hope it works!

  2. It appears that the 20 mph zones are working or the city is experimenting with other neighborhoods/street qualities. According to an article from Streetsblog on July 10, 2012, NYC announced that they have selected 13 additional sites where the "slow zone" treatment will be implemented.

    NYC DOT was inundated with requests as the neighborhoods have embraced them. In addition, the safety benefits tied to 20 mph zones are significant. NYC Transportation Commissioner Janette Sadik Khan said, "The safety benefits of capping vehicle speeds at 20 mph are tremendous, with pedestrian survival rates at 95 percent in the event of a crash at that speed."

    In contrast, according to America Walks, pedestrian survival rates at vehicles traveling 30 mph are 60 percent.

    Clearly the "slow zones" can be an effective way of mitigating pedestrian/bicycle related injuries and deaths. Moreover, it also allows pedestrians and bicyclists to more readily coexist on the street when the vehicle speeds are decreased to 20 mph.

    As vehicle speed increases motorists get "tunnel vision" meaning their peripheral vision decreases.

    In effect, establishing a more pedestrian-oriented environment is better for all modes.

    Additional reading:

    Streetsblog article "NYC Will Expand 20 mph Zones to 13 Neighborhoods, With More to Come"

    "New Chicago Plan: Pedestrians Come First"


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