http://www.dasa.mod.uk/publications/...ember_2012.pdf
Quite hard for anyone responsible for the safety of their people to ignore the statistics of higher risk in that report.
I can't find any figures for the financial cost. With the MoD being 'self-insuring' for all road vehicles, the cost to defence per accident is very large as they pay for everything including compensation to other parties. I have seen a few presentations by the MoD team responsible for this in the past and 'cost per crash' is a big enough number to warrant some effort to reduce.
The MT Trade is still proud of being professional at operating vehicles.