Geographic Information Systems (GIS) are computer tools to analyze and visualize data on a map. GIS is widely used in transportation planning for various types of applications. Recently, the Bipartisan Infrastructure Law (BIL) established the Safe Streets & Roads for All (SS4A) program and appropriated $5 billion over five years. To qualify for implementation funding for safety projects, grant applicants must have completed a safety action plan, which is a comprehensive plan aimed at reducing and eliminating serious injury and fatal crashes. Key parts of a safety action plan include an analysis of crashes trends and locations, a geospatial identification of higher risk locations, and an identification of underserved communities using data. GIS allows us to meet the requirements of safety action plans and provide our clients with relevant and valuable information to make their streets and roads safer for everyone.
Utilizing ArcGIS Dashboards, our custom-made dashboard tools present location-based analytics and interactive data visualizations. For the Danville Area Transportation Study (DATS), we built a dashboard with crash type and location type selectors, a trendline, and an insights panel that illustrates crash severity as well as weather, surface, and lighting conditions.
A high injury network (HIN) is a common strategy for identifying and prioritizing locations for safety improvements in a safety action plan. For St. Charles County, using a series of GIS tools, we developed a methodology that identified a HIN that represents approximately 9% of roadway mileage but 73% of fatal crashes and over half of all bicycle and pedestrian involved crashes.
As previously mentioned, a data-informed identification of underserved communities is a requirement of safety action plans and a best practice for reducing the disparate economic, environmental, and health burdens experienced by disadvantaged and underserved communities. Using GIS and census data, we developed an equity index score for census tracts in Vermilion County, Illinois. We use this data to identify equitable target areas (ETAs) that helped the project team focus targeted outreach efforts during the public engagement phase as well as prioritize safety projects when overlayed with the HIN.
Safety analysis and safety planning require large amounts of data. GIS allows us to effectively manage, analyze, and visualize these data to make valuable information available for our clients and the public. To see how these GIS elements, and others, fit together to form a safety action plan, visit the Vermilion County Safety Action Plan StoryMap.