Which tools can I use to determine the 10 worst intersections in a State by analyzing the crash data? What we have is the point of all intersections and all crashes point. The output we want is a hotspot map for all ring buffers around the intersection with the crash numbers in each ring buffer.
You could try the following tools to achieve what you want:
Buffer: create the ring buffers around the intersections.
Summarize Within: calculate the number of crashes within each buffer [Input Polygon: Buffer / Input Summary Feature: crash points].
Sort the attribute table of the Output to select the 10 worst intersections and map them.
(I'm not sure if you also want to apply this step) Hot Spot Analysis or Optimized Hot Spot Analysis Tool: find statistically significant hot spots of crashes [Input Feature Class: the Output of #2 / Input Field: crash numbers]
Thanks for your answer! It works for finding 10 worst intersections. However, I still have the problem with Hot Spot Analysis. Since I only want to obtain a Hot Spot Map for intersection buffers (all pink ring buffers), which means my polygon are not contiguous, and I tried to use the tool that you recommended, but it failed to output. May I have any suggestion for that? Thank you very much!
What exactly is the end result that you want to achieve?
I'm not sure about the error message, but maybe the approach also has to be reconsidered. For example:
Does the screenshot show your total study area, and crashes only occur within the buffer polygons? Then probably instead of a Hot Spot Analysis it would be better to use the data as it is now to map them, for exampling using Graduated Colors, Graduated Symbols or Proportional Symbols on the Field Crash Numbers to show the amount of crashes within a buffer polygon.
You could run the Hot Spot Analysis on all of your crash points instead of the buffers. Then you will get the "real" hot spots instead of using an aggregated number as Input.