WASHINGTON, D.C. --- The U.S. average retail price for regular gasoline, as of Oct. 16, fell 3.5 cents to hit $2.226 per gallon, according to the Energy Department. That's 49.9 cents lower than a year ago. The Energy Department's Energy Information Administration (EIA) reported that East Coast prices fell 3.4 cents to $2.207 per gallon, 55.9 cents lower than at this time last year. The Midwest saw prices fall 2.4 cents to $2.129 per gallon, while the Rocky Mountains price fell 7.7 cents to $2.414 per gallon. West Coast prices were still the highest in the nation after falling 5.8 cents to $2.509 per gallon. California prices fell by 6.1 cents to $2.540 per gallon. Retail diesel fuel prices fell by 0.3 cent to reach $2.503 per gallon, the EIA reported. That's 64.5 cents lower than last year. This is the ninth week in a row that overall diesel prices have fallen, but some regions saw slight increases. East Coast diesel prices fell 1.2 cents to $2.521 per gallon, but Midwest prices rose slightly, by 1.1 cent, to $2.459 per gallon. The Gulf Coast saw a 1.5 cent rise to $2.461 per gallon. The Rocky Mountains and West Coast saw slightly larger decreases in diesel prices, with the Rocky Mountains falling 4.5 cents to $2.539 per gallon and the West Coast dropping 4.2 cents to $2.655 per gallon.