In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria' s roads but are involved in 12 percent of all highway fatalities  The very largest trucks-those with three trailers-had less than a third of the accident rate of single- and double-trailer trucks
Clearly, ttherefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks
So far only the best, most experienced drivers for Partorian trucking companies have been driving triple-trailer trucks.