After a streaky rally by the main truck fuel, a gallon of diesel plunged half a cent to $3.124 a gallon.

According to the energy administration, the price of diesel has fallen for four weeks totaling 7 cents and before March 29 the price of diesel had risen to 82.2 cents, and the cost of diesel fell in five of the 10 regions surveyed where three increased and in two it remained stable, and the largest decrease was 2.4 cents in the Rocky Mountain region. 

This is how the on-road price of diesel fuel looks according to EIA.gov: 

Taken from: ttnews.com