https://wccftech.com/pixel-4s-personal-safety-app-can-now-be-sideloaded-on-older-pixels/

One of the lesser-known features of the Google Pixel 4 was car crash detection. It launched alongside the device and only works in the United States for now. Furthermore, it was a Pixel 4 exclusive, with no word about when it would make its way to older devices. Now, XDA Developers has managed to extract version 1.1.286909525  of the Personal Safety app from the Android 11 developer preview. You can now sideload it on any Google Pixel phone.

Car Crash Detection is a part of the Pixel's Personal Safety app. It uses your phone's location, accelerometer, and microphone data to determine if you and your vehicle have been involved in a collision. If your Pixel thinks that you’ve been in a car accident, then the Personal Safety app will play a loud sound and then ask if you need further assistance. If you interact with the app stating you're ok, the phone will then ask you what went wrong. You'll still have the ability to contact emergency services, though.