High Injury Network

High Injury Network. Developed by DOMI using City and PennDOT data. Methodology can be found in the description. This data is obtained from the [City of Pittsburgh's GIS Portal](https://pghgishub-pittsburghpa.opendata.arcgis.com/) on a weekly basis.

## High Injury Network (HIN) Development Methodology

The purpose of developing a High Injury Network (HIN) is to identify and prioritize areas with high frequencies of traffic-related injuries and fatalities. The goal of developing the HIN is to increase road safety by focusing resources and improvements on high-risk areas. The development of a HIN is an important piece of Vision Zero. Vision Zero sets a clear goal of zero fatalities and severe injuries on roadways, while the HIN identifies and prioritizes areas where these incidents are most prevalent.

This analysis uses the City’s Street Centerline GIS data and PennDOT five (5) year reported traffic crash data from 2018-2022. Other assumptions used in the development of the network are outlined in this document.

**The Network:**

There are 2,423 miles of roadways in the city of Pittsburgh. 

For this analysis:

  • We focused on surface streets and excluded limited access facilities including interstates, ramps, facilities with no city-maintained components (Example-Rt 65) and tunnels. Most traffic incidents occur on surface streets in urban areas. These are also the streets that will have the highest pedestrian, bicycle and vehicle interactions, making them crucial areas for safety.

  • We included all streets regardless of facility owner (i.e., city, state or county ownership). This is because even if the city does not have direct oversight of the roadway, it is important for us to know where crashes are occurring. Additionally, while the city may not own the roadway, in many cases the city own signal equipment, streetlights and/or have oversight over other aspects of the roadway that might be opportunities for safety intervention.

**Injury Crash Data and network development strategies**

We developed a methodology to translate injury crash data into insights on roadway safety. Crashes without a reported or suspected injury are not included in the analysis.  

We included all Fatal and Injury Crash (FIC) data including suspected serious injury, suspected minor injury, and possible injury to identify HIN corridors. Many traditional HIN's factor only serious and fatal injuries. The reason we used 'all-injury crashes' was to eliminate the possibility of any discrepancies or subjectivity in police crash reports. This allowed us to have a broader sample size which help us identify injury crash hotspots proactively before they may result in greater injury or even a fatality crash without proper interventions.  This strategy also ensures a holistic view of the road system and its vulnerability which is the core of the concept of "Safe System Approach".

The team conducted a GIS analysis to identify the high injury network. The injury and crash network reflect: 

  • Roadway segments with 5 or more injury crashes within 1500 ft, along with any segments lying between them, were combined to define a corridor. 

  • Individual roadway segments with 2 or more serious or fatal injury crashes within 200 ft to each other but the overall injury crash count of the segment is less than 5.

  • We manually reviewed crashes occurring at or near intersections to ensure that crashes were appropriately assigned to the primary or secondary street. 

**Factoring in Vulnerable Road Users**

A Vulnerable Road User (VRU) is defined as a non- motorist and someone who is walking, biking, rolling, or using a mobility device, such as a wheelchair ([PennDOT, 2023](https://www.penndot.pa.gov/TravelInPA/Safety/Documents/A-%20VRU%20Safety%20Assessment%20Report%20-%20Single%20Pages_Proof%207.pdf)). VRU's are of critical concern and a priority for DOMI as they are at heightened risk of severe injury or fatality as a result of a vehicle crash.

While VRU crashes are included in the development of the HIN, the team identified Top 10 segments with high pedestrian or bicycle crashes that didn’t meet the threshold for inclusion of the high injury network.

Finally, this analysis included findings from the [Pennsylvania VRU Safety Assessment Report](https://www.penndot.pa.gov/TravelInPA/Safety/Documents/A-%20VRU%20Safety%20Assessment%20Report%20-%20Single%20Pages_Proof%207.pdf). The HIN network included both the **identified high-risk areas** and **systemic safety focused** identified urban segments and intersections from the report. As expected, almost all of these data points were already identified from the previous phases of analysis. Data that were missing was incorporated into the HIN. 

Tags: _etl, accidental, crash, safety, vehicle, vision zero
Organization: City of Pittsburgh