Experts all have their opinions and that's fair enough, though studying anything doesn't make one immune to fashion, prejudice,financial incentives, personal taste or groupthink. Eugenics,for example was very popular(and almost self evident) amongst the "educated classes" and opinion leaders a century ago. NeoMalthusianism a la Erhlich was very popular too and still is, despite being a crock(or at the very best, highly debatable). All that is to say that there's no need to worship experts on any matter. As you bring up vaccines, I'd say that plumbers and drainers have saved more lives than vaccines. So, I am perfectly happy for you to have as many vaccines as you want, just leave me and mine out of it.
As for road safety, roads are much safer now than they ever were. The question of how much effort to get the road toll down further and when do diminishing returns kick in is yet to be answered.Sure, road accidents are shocking especially if someone we know is involved but that doesn't mean much in the big picture.
An interesting case is what happened in Holland where the town of Drachten abolished traffic lights,road signs and road markings. Accidents and injuries are way down. The key thing is that without all the rules, people don't have a false sense of security and so take more care. http://www.examiner.com/article/at-least-with-traffic-fewer-rules-make-for-better-behavior
