A systemic approach to pedestrian safety analysis

By Saumya Jain

Figure by NCHRP: A systemic approach addresses sites with similar risk factors, regardless of crash history. The approach falls along a spectrum of other approaches to safety that are more or less proactive in treating sites based on risk or prior crash history.

According to the Fatality Analysis Reporting System data, in the last decade 12 percent of all traffic fatalities were pedestrian fatalities, amounting to more than 49,000 deaths. Numbers from the last few years have shown a rise in this percentage. Concerned with these alarming statistics, DOTs and local planning organizations have focused efforts toward designing methodologies for pedestrian safety analyses. But most of these methodologies follow the “hot spot” approach, where improvements are only made to specific locations with historically high crash incidents, making this approach reactive rather than proactive. TRB’s National Cooperative Highway Research Program recently released a guidebook that outlines a systemic approach for proactively identifying high risk zones and prioritizing countermeasures.

The report describes its systemic approach as a data-intensive research methodology that not only takes into consideration crash rates and locations but also studies network characteristics, land uses, and surrounding demographics that can be associated with specific crash types and severity. This helps identify high risk locations based on key risk factors and characteristics, even in areas where crash data is sparse. The report acknowledges that different regions may possess different risk factors and thus recommends all organizations conduct individual regional analyses for identifying location-specific key factors.

This is not the first time that data other than crash rates are being used in identifying high-risk zones. In 2016, researchers at Columbia University used Walk Scores to estimate pedestrian activity and consequently identify potential high-crash locations. A 2017 study for Florida DOT highlights a range of factors contributing to pedestrian deaths in the state. A key finding of that report was that low-income neighborhoods are disproportionately susceptible to pedestrian deaths. Perhaps more importantly, it identifies “pre-conditions” for greater pedestrian hazard. As pointed out in a recent urbanist blog, these pre-conditions include the presence of big box stores, discount stores, convenience stores, and fast food restaurants associating high risk with automobile-oriented design, higher speeds, and bad lighting.

Though the NCHRP report is not the first to introduce decision makers to proactive pedestrian safety analysis, it is a good practitioner-ready resource with step-by-step guidance on conducting pedestrian safety analysis and contains four case studies highlighting early implementations of systemic approaches to pedestrian safety analysis. The seven-step process is designed to be highly compatible with the HSM safety management, which is already used by many DOTs, making it easily adoptable.

Saumya Jain is a Senior Associate at SSTI.