ADS and ADAS are different datasets

Why can't these two crash numbers be added together?

Reporting obligations behind it

The filings a company is required to make that this figure is built from

Known biases ledgered

Each carrying the direction it pushes the figure, rather than a warning that data may be imperfect

Of those, unsigned

Entries where the record does not say which way the error runs

Formula

Unit: reports

Two separate files under one Standing General Order. Never summed.

Federal crash reporting for automated driving systems, under Standing General Order 2021-01
Federal crash reporting for driver-assistance systems, under the same order

Each known problem with this number, and which way it pushes it. A signed direction is more useful than a warning that data may be imperfect.

Direction is the sign of the error, not its size: an overstating source pushes the figure up, an understating one pushes it down, and a direction unknown means the record does not say which.
		Effect
Category confusion	overstates	ADS is a vehicle driving itself. ADAS is a human driving with assistance — lane keeping, adaptive cruise. Summing them inflates any robotaxi crash count by thousands, most of them Tesla vehicles with a person at the wheel.
No rows match this filter.

Every step that changes the answer, in the order it happens. Nothing here is a summary of a longer method: this is the method.

Count the two files separately, latest version of each report, excluding the filings that add no new information.
Publish the two counts side by side and never add them. That is the whole metric: the number is a demonstration that one total does not exist.

Any robotaxi total. Only the ADS file describes vehicles operating without a driver.