High-high cluster and high-low outlier road intersections for road traffic crashes within the CoCT in 2017, 2018, 2019 and 2021

This dataset offers a detailed inventory of road intersections and their corresponding suburbs within Cape Town, meticulously curated to highlight instances of high crash counts observed in "high-high" cluster and "high-low" outlier fishnet grid cells across the years 2017, 2018, 2019, and 2021. To enhance its utility, the dataset meticulously colour-codes each month associated with elevated crash occurrences, providing a nuanced perspective. Furthermore, the dataset categorises road intersections based on their placement within "high-high" clusters (marked with pink tabs) or "high-low" outlier cells (indicated by red tabs). For ease of navigation, the intersections are further organised alphabetically by suburb name, ensuring accessibility and clarity.

Data Specifics

Data Type: Geospatial-temporal categorical data with numeric attributes

File Format: Word document (.docx)

Size: 602 KB

Number of Files: The dataset contains a total of 625 road intersection records (606 "high-high" cluster and 19 "high-low" outliers)

Date Created: 21st May 2024

Methodology

Data Collection Method: The descriptive road traffic crash data per crash victim involved in the crashes was obtained from the City of Cape Town Network Information

Software: ArcGIS Pro, Open Refine, Python, SQL

Processing Steps: The raw road traffic crash data underwent a comprehensive refining process using Python software. Following this, duplicate crash records were eliminated to retain only one entry per crash. Subsequently, the data underwent further refinement with Open Refine software, focusing specifically on isolating unique crash descriptions for subsequent geocoding in ArcGIS Pro. Notably, during this process, only the road intersection crashes were retained, as they were the only crashes that were able to be spatially defined.

Once geocoded, the road traffic crash data underwent rigorous spatio-temporal analyses, encompassing spatial autocorrelation, hotspot analysis, and cluster and outlier analysis. Leveraging these methods, road intersections identified as either "high-high" clusters or "high-low" outliers were extracted for inclusion in the dataset.

Geospatial Information

Spatial Coverage:

West Bounding Coordinate: 18°20'E

East Bounding Coordinate: 19°05'E

North Bounding Coordinate: 33°25'S

South Bounding Coordinate: 34°25'S

Coordinate System: South African Reference System (Lo19) using the Universal Transverse Mercator projection

Temporal Information

Temporal Coverage:

Start Date: 01/01/2017

End Date: 31/12/2021 (2020 data omitted)