Dozens of commercial truck drivers honked their horns as they circled the U.S. Capitol Thursday to protest the rising cost of diesel fuel.

The drivers looped around the National Mall in Washington D.C. to draw attention to an issue they say is hurting their livelihood.

The average U.S. price of diesel fuel is $1.06 per liter.  That is up from 76 cents per liter a year ago.

Meanwhile, the average price of unleaded gasoline in the United States is 88 cents per liter.  That is up from 73 cents per liter this time last year.