By Kyle Hearing

Since 2014, the Bicycle Coalition has been urging the City of Philadelphia to adopt Vision Zero. In early 2015, it called for Philadelphia to adopt a Vision Zero policy in its Better Mobility mayoral platform. In the fall of 2015, BCGP hosted the first Vision Zero for Philadelphia Conference and the helped to launch the Vision Zero Alliance in fall of 2016.

Shortly thereafter, Mayor Kenney publicly announced the City’s commitment to ending serious injuries and deaths on Philadelphia streets by 2030; almost exactly one year later, Philadelphia’s Office of Transportation and Infrastructure Systems (oTIS) released the Vision Zero Three-Year Action Plan.

In preparation for the Bicycle Coalition’s Vision Zero for Philadelphia 2018 Conference, we wanted to review what did and did not make it into the plan. Since there is a lot to digest, we will be doing this week by week, starting with an examination of the High Injury Network. The Action Plan’s author, Kelley Yemen, will be speaking at the March 17th conference.

The Vision Zero High Injury Network (highlighted in yellow below) represents the 12% of Philadelphia streets responsible for 50 percent of all traffic deaths and severe injuries that occurred from 2012 to 2016. By understanding which streets are most dangerous, oTIS can plan infrastructure improvements where they are needed most.

The identification of the High Injury Network started with crash data obtained from PennDOT. This data is collected from police departments across the state, standardized, and released once a year, generally a full calendar year later (if you follow our page, you know this process takes a while). This database includes considerable amounts of data; however, to create the High Injury Network, oTIS focused on the location and type of road users involved in crashes which resulted in “Severe Injuries” and fatalities.

These crashes were identified as occurring either “mid-block” or within an intersection and mapped to the nearest street segment or intersection accordingly. Street segments were consolidated into corridors which were then evaluated to determine the frequency with which crashes occurred; the distinction between crashes occurring mid-block vs. within an intersection is important here, as intersection crashes are counted towards each street’s corridor.

Once crashes were assigned to corridors, pedestrian and bicyclist serious injuries and fatalities were weighted to account for the fact that crashes involving pedestrians and bicyclists are far more likely to result in serious injuries and fatalities. Finally, corridor scores were normalized by length, allowing for the identification of the most dangerous corridors in Philadelphia, or the High Injury Network.

For a far more in-depth look at the methodology underlying the High Injury Network, take a look at oTIS’ Vision Zero web mapping application.

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