According to the book, most road deaths involve sober drivers who are not speeding.
Although there are no perfect answers, I think that the money should go toward building safer roads and maintaining the roads we currently have. There isn't enough money to maintain our roads and therefore keep them safe.
But we're dealing with a failure in American politics and public health. Public and political interest--and therefore money--is being diverted to the items of greatest emotional interest, not the areas of greatest risk.
If I could, I'd slash the TSA into a much smaller, much simpler, much cheaper organization. Then I'd protect the safety of the "homeland" by building safer roads, ending tobacco addiction, and preventing the spread of HIV. But that just seems way to rational for Washington.