[this gathered and extended from two recent posts I've made in the Cumbria Speed Camera Partnership forum.]
Research by Professor Noland:
http://www.cts.cv.ic.ac.uk/documents/pu ... s00197.pdf
contains:
"To put these results in context, the total reduction in fatalities was about 2100 over this time period (for the 9 regions). Therefore, medical technology improvements may be accounting for nearly one-third of this reduction. Overall, these results strongly support the hypothesis that changes in medical care and technology have played an important role in reducing traffic-related fatalities."
I think I interpret this correctly if I say: Over the 20 years from 1980 to 2000 traffic fatalities in GB dropped from 6,010 to 3,409, meaning that around 2,600 fewer fatalities are taking place each year. Of this figure, Professor Noland believes that around 1/3rd are the result of medical care improvements, amounting to something around 850 lives now being saved each year due to 20 years' improvements. I'm a little worried that he doesn't mention the change in rate of fatality improvements - clearly almost all of the improvement took place in the 1980s. It seems to me that it may be unwise to treat the two periods (Up to 1993 and after 1993) as similar, when clearly they were quite different.
I'm now sure that there's another version of the paper that pulls out a slightly clearer conclusion, but I can't find it.
The clue might be on this page:
http://www.cts.cv.ic.ac.uk/html/Researc ... tionID=197
Where the text refers to a 2004 document, but the download is a 2002 document.
I think the evidence (and supporting logic) is very good in suggesting and supporting the idea that we have an ongoing improvement in post accident care that should be delivering a regular reduction in roads fatalities. We might reasonably calculate that the medical care improvements are worth a bit more than 1.5% per annum reduction in roads fatalities.