Every time you get into a car, there is a non-zero chance that you might get injured, or worse, die. The probability of this happening depends largely on where you're driving and, of course, how much you drive. However, there are a few different ways to measure this statistical risk. A recent Bloomberg article by David Zipper highlights one ongoing debate.
The three most common methods are:
Road deaths per capita
Road deaths per registered vehicle
Road deaths per distance traveled
In my opinion, options 1 and 3 seem the most relevant. Option 1 is useful because it measures a citizen's overall risk and allows driving risk to be easily compared to other causes of death (which tend to be measured on a per capita basis). The limitation is that it is harder to compare a country where everybody drives to a country where few people drive.
That's where option 3 comes in. In theory, it provides the best indicator of road risk by accounting for distance traveled, which is the primary argument for why it's commonly used in the US where the car is king. But it does "dilute" the fatality count the more people drive, and it hides overall car dependency. In his article, Zipper likens this approach to measuring cancer deaths per cigarette smoked.
In any event, here is how both methods appear in the International Transport Forum's 2025 Annual Road Safety Report (which is cited in the article):
