This paper presents a five-step methodology developed in Bogotá to identify critical road safety locations using historical, georeferenced data on crashes involving killed and injured pedestrians, cyclists, and motorcyclists. The methodology was applied to data from 2019 to 2023 across arterial and nonarterial roads in Bogota, providing a city-level analysis of critical locations. The methodology can be applied to other cities—especially in LMICs—to help them identify with more clarity where road safety interventions are most needed, making effective use of their limited resources.

This paper is divided into two sections:

Section 1: A step-by-step description of the methodology developed by WRI to identify critical locations in Bogota, Colombia, including:

  1. Gather georeferenced crash data, and define a proper time frame.
  2. Define the road network and scales of analysis.
  3. Perform geographical analyses by calibrating adequate search radii values.
  4. Visualize the results discriminated by different types of roads, road users, and geographic scales.
  5. Include other additional analysis that might be relevant to the context by revealing actionable information that leads to more robust findings.

Section 2: Conclusions and recommendations for applying this methodology in other cities

Key Findings

  • Low- and middle-income cities usually have limited resources for road safety, so they need to be able to identify the most critical locations where improving road safety is most urgent and yields the greatest benefits.
  • Our methodology uses a combination of geographic concentration (kernel) and spatial autocorrelation analyses (cluster) in arterial and nonarterial roads to identify locations with the highest concentrations of road crash victims in Bogotá, Colombia.
  • In Bogotá, these serious crashes are clustered in middle- to low-income areas, where structural inequalities and segregation appear to be related to traffic fatalities and injuries.
  • This methodology identified locations in Bogotá where serious crashes have occurred frequently and in a systematic form. In these locations, local authorities should consider future road safety interventions.
  • To adapt and use this methodology, other cities need geocoded data differentiated by road types and victims.

Summary

This paper presents a methodology developed in Bogotá to identify critical road safety locations. These are sites with high crash rates of killed and injured pedestrians, cyclists, and motorcyclists, who are referred to in the text as vulnerable road users. In this document, we analyze georeferenced data on traffic deaths and injuries in Bogotá between 2019 and 2023 on arterial and nonarterial roads to identify critical locations at the city level. There are five steps defined in the step-by-step process of designing and implementing this methodology. After gathering georeferenced data on serious injuries and fatalities (step 1), the data can be adjusted to different road network scales (step 2); and for the case of Bogotá, we divide the road network into arterial and nonarterial roads. By applying a combination of geographic concentration (kernel) and spatial autocorrelation (cluster) analyses, we can determine where critical corridors and critical spots are located (step 3) and then visualize them (step 4). These analyses can be complemented with additional information available (step 5), such as type and characteristics (such as age, gender, etc.) of road users, land use, income level, speeds, and so forth to have a more comprehensive grasp of where the critical spots and corridors are located, which built environment factors have an influence on their appearance, and whom they affect.

We developed this methodology based on best practices and international references as well as extensive discussions with experts from the Bloomberg Philanthropies Initiative for Global Road Safety and the District Mobility Secretariat of Bogotá. It is a tool that can help Bogotá pursue its goal of reducing deaths and serious injuries from road crashes to zero, as stated in the Road Safety Plan. Other cities can also use this methodological framework to reduce traffic injuries and fatalities.

This Working Paper was made possible through funding from the Bloomberg Initiative for Global Road Safety (BIGRS).