Societies can already reduce road deaths to nearly zero, it's cheap, it's easy, and it's fun. It's just redirecting all of the cash we spend on vehicles/cars/highways/roadways/signs/etc into public infrastructure that is all encompassing.
A hundred billion dollars a year [0] on construction (reading the definition I'm not 100% sure what is included in this due to how definitions can be hazy) has goes a long way, not to mention the amount we spend on gasoline, car maintenance, etc etc.
The reason I say it's fun, is because I love being on a train. First time I was able to ride one, which due to living in the good old USA wasn't until I was 23, I yelled "I'm on a train" . The Germans traveling with me weren't as into it.