I have previously posted on how inadequate current insurance limits are on tractor trailers. In that blog post I stated (regarding the minimum $750K  limits being inadequate for catastrophic wrecks, limits having not been increased in almost 3 decades): 

 If you go to any present value calculator on the Internet and use a 4% inflation rate you will find that the present value of $750,000, 29 years from now, is about $240,000 in today’s dollars. To put it another way, you would need $3,120,000 in today’s dollars to equal $750,000 in 1980.

A new actuarial study, sponsored by The Trucking Alliance, has found that trucking companies insured at the $750,000 level are, in effect, uninsured. “They are just rolling the dice that they don’t have an accident,” Lane Kidd, president of the Arkansas Trucking Association and an Alliance member stated.

The study included data on more than 8,600 truck accident settlements between 2005 and 2011. An article on the study can be found HERE 

I note many safety groups, and my own firm, agree that insurance minimum limits need to increase for all truck and bus companies.