Each year, Allegheny County publishes an update to the County crash dataset, joining together data published by PennDOT (the Pennsylvania Department of Transportation) after filtering it down to vehicular crashes that took place in Allegheny County in the previous calendar year. There are individual tables for each year, with record-level data going back to 2004. This dataset has now been updated with the crash data for 2024.
There have been some changes to the PennDOT data format over the years, and the dataset has accommodated this by standardizing the published set of fields from 2017 onward. All the records are compiled into a single cumulative table for ease of analysis.
It's interesting to study the total number of reported crashes in Allegheny County by year from 2004 to 2024.
year | crashes |
---|---|
2004 | 12535 |
2005 | 12215 |
2006 | 11747 |
2007 | 12238 |
2008 | 11858 |
2009 | 11677 |
2010 | 11320 |
2011 | 12189 |
2012 | 12230 |
2013 | 11994 |
2014 | 12182 |
2015 | 12735 |
2016 | 12908 |
2017 | 12537 |
2018 | 12417 |
2019 | 12253 |
2020 | 9863 |
2021 | 11726 |
2022 | 11588 |
2023 | 10370 |
2024 | 10228 |
Aside from an abrupt dip in 2020 (a decrease in crashes which started in March of 2020 and could be attributed to decreased travel during the first year of the pandemic), countywide crash counts have decreased year over year since 2016. (The statewide variation in crashes by year (not shown here) exhibits a similar pattern to the countywide trend.)
These tables have almost 200 columns, which provide details about each crash, including how many vehicles/bikes/pedestrians were involved; the weather, condition of the road, and the lighting at the crash scene; the latitude and longitude of the crash site (though note that they are in the nonstandardly named `DEC_LAT` and `DEC_LON` fields); and whether any driver was using a cell phone, had been drinking, ran a stop sign, or ran a red light. With this data, you can ask and begin to answer questions like "What is the relationship between the speed limit of the road (or whether any speeding was involved in the accident) and the severity of the accident?".
The Allegheny County Crash Data dataset also links to a PennDOT page where you can download the raw data, and a primer from PennDOT on the crash data and how it is assembled.