Roger Pomerleau writes:

I lowered the maximum speed on my commercial fleet of 60 Tractor Trailers by 4 MPH and saved 70,000 gallons of diesel fuel in a year... that's $300,000.

If the speed limit could be maxed at 55 I could save 150,000 gallons more or an additional $ 675,000.

It is just not safe to drive tractor trailers at 55 until the law is changed.