We’ve now had four reasonably sharp weekly declines in the national average price of diesel fuel. While retail prices have dropped more than 41 cents a gallon over that span, the average is still astronomically high — $1.506 more than the average one year ago.

The national diesel average declined 14.9 cents last week to $4.353 a gallon, the fourth straight drop that has lowered the price of trucking’s main fuel by 41.1 cents a gallon, the Department of Energy reported.

Canadian transportation firm Mullen Group Income Fund’s second-quarter profit rose to C$19.9 million, or 25 cents a unit, from C$16.6 million, or 21 cents, a year ago.

Logistics firm US1 Industries said its second-quarter net income slipped to $813,000, or 6 cents a share, from $1.1 million, or 9 cents, a year ago.

The cost advantage offered by shipping direct and avoiding paying for warehousing and inventory is dwindling, possibly forever, as the price of fuel rises. As a result, more carriers have started looking at warehousing to play a larger role in the logistics process.

The cost of retail diesel fell another 10.1 cents last week to $4.502 a gallon, the third-straight weekly decline in the national average that has cut 26.2 cents from trucking’s main fuel, the U.S. Department of Energy said.

Canadian firm Contrans Income Fund’s second-quarter income rose compared with a year ago, due largely to a big income tax charge in the previous second quarter.