https://injuryfacts.nsc.org/motor-vehicle/overview/introduction
Since 2014, fatality rates have been increasing. The above data, however, is not adjusted for an increase in drivers, the changing demographics (ages) of drivers, nor for the total number of miles driven. In general, the number of drivers on the road increases each year, and the number of miles driven per driver also usually increases each year.
The NSC counts both vehicle and non-traffic related fatalities (crashes occurring on private roads, parking lots, etc), and includes deaths that occur within one year of a crash, which together add about 2,000 additional fatalities to the annual total.
I have a hunch that changing demographics might explain much of this rise.
