Gasoline and diesel prices fell again this week, marking the third straight week in December the prices at the pump have gone down.

Diesel prices fell on average 4.6 cents nationwide this week to land at $3.95 per gallon. While these prices have come down in recent weeks, the price per gallon for diesel is still approximately 11 cents more per gallon than it was last year at this time, according to the U.S. Energy Information Administration's report.

There are some regions where prices above the $4 mark are still common. The state of California and the New England and Central Atlantic regions are still experiencing diesel prices above $4. New England's average price for a gallon of diesel is the highest of anywhere else in the country right now at $4.16 per gallon.

Gasoline prices also fell again this week an average of 9.5 cents per gallon to rest at a national average of $3.25 per gallon. That is only 2.5 cents above where the price of gasoline was last year at this time.

As with diesel prices, the most expensive gasoline can be found on the East Coast, with New England's price per gallon at $3.49.

Today U.S. light, sweet crude futures rose 47 cents, so the price per barrel settled at $87.20. Compared with a year earlier, however, the price of West Texas Intermediate oil was down 7.3%, notes the American Trucking Associations.

The uptick was due to news that a key U.S. pipeline expansion will be completed next month, along with optimism about a deal to avoid the "fiscal cliff," according to Reuters.

Enterprise Products Partners LP and partner Enbridge Inc are expected to complete a 350,000-barrel-per-day expansion to the 150,000-bpd Oklahoma-to-Texas Seaway pipeline in early January.