We had 38,680 motor vehicle deaths in 2020. We haven't had 45,000 since 1989; 54,000 in 1972. The rate has been steadily decreasing (with a few ups and downs along the way) for about the last 50 years(1), even though miles driven has been steadily increasing(2). This is because we, as a society, as a government, decided to study the problem and implement changes to improve the situation.
[1] https://www.vox.com/22675358/us-car-deaths-year-traffic-covi...