What happened
The national average price of gasoline fell below $4 per gallon on Tuesday, according to AAA. The average reached $3.9788 per gallon.
The decline follows increases during September and October. A week earlier, the average price was around $4.15 per gallon. One month ago, gasoline averaged $4.37 per gallon.
The price of diesel also decreased, falling to $6.1572 per gallon from $6.2875 a week ago.
California continues to have the most expensive gasoline in the United States, averaging $5.71 per gallon. North Carolina has the lowest average gas price at $3.24 per gallon.