To request data from the California Highway Patrol, go to the Statewide Integrated Traffic Records System (SWITRS) website and register an account. When your account is registered and activated, login and click "Raw Data" on the left hand sidebar, as circled below:
Fill in the form that comes up. Make sure to fill in the "Reporting Period Start" and the "Reporting Period End" fields and check the "Headers" box. When you are done hit "Generate Report". These fields are boxed in red below:
The CHP will email you when your report is ready for download, which normally takes a few days. The download will give you a large zip file which you must unzip before using SWITRS-2-SQLite.