What else could make life safer at a realistic cost for people outside of vehicles?

Urban planning that separates pedestrians and vehicles.

Roads that are narrow in places where a lower speed is desirable.

Heavy taxation on vehicles with more mass and lower visibility.

Actual licensing standards other than driving down a couple of city streets and parking.

More crossings, with lights or bridges, instead of long four-lane arterial roads with nowhere to safely cross.

Where I live, the speed limit keeps getting reduced so the city can make money off of fines, especially because nobody follows speed limits that are ridiculously low for wide, straight roads where following the limit would make traffic ground to a halt.