According to today's USDA Grain Transportation Report, for the week ending December 5, the U.S. average diesel fuel pricedecreased 17.4 cents from the previous week to $4.967 per gallon, 129.3 cents above the same week last year.

This was the first time since October that the diesel price had fallen below $5 per gallon.

It was also the largest drop since July 25 when the diesel price dropped by 16.4 cents and—before that—October 27, 2008, when the diesel price declined by 19.4 cents.

In the agriculture-producing Midwest, the diesel price dropped by 20.1 cents to $4.907 per gallon.

Last month, amid widespread fuel shortages, several Midwestern States temporarily waived hours-of-service (HOS) regulations for truck drivers hauling fuel.