In the UK pedestrian car collisions are falling, despite increased amounts of cars and distances walked. In the US pedestrian collisions are at high.
I don’t think it’s the safety features in cars that matter here. Similar features are going to be present in the UK as the US. People in the US are buying bigger and bigger trucks. They also have less walkable cities (this could also improve in the UK). They should be taxing larger vehicles more. Get them off the road, they have larger blind spots and greater injury on impact.