Michigan's average gas price has remained high despite earlier predictions of price drops.

The average price for a gallon of regular unleaded fuel is $3.99, unchanged from a week ago, according to Dearborn-based auto club AAA Michigan. That’s up from $3.68 one year ago.

Refinery and pipeline problems from late July caused the initial spike in prices. It typically takes longer for prices to drop back down, but the stagnation is surprising to Nancy Cain of AAA.

She said she had expected some relief at the pump, but prices remain above the $4 mark in many areas.

The Marquette area has the highest average price of $4.04 compared to the nine other metro areas in AAA's fuel gauge report. The Lansing area has the least expensive average price of $3.93 per gallon.

AAA bases its report on a survey of 2,800 Michigan gas stations. Today’s price report is based on the last credit card transaction at each station on Sunday.

The national average is $3.70 per gallon, up 8 cents from last week and 10 cents higher than one year ago.

Michigan has the fourth-highest gas price in the nation. Hawaii has the highest average price at $4.17 per gallon, while Arizona has the lowest price at $3.37 per gallon.

The lowest price reported on www.michigangasprices.com this morning was $3.58 at Kroger in Monroe County's Lambertville. The highest price on the site this morning was $4.51 at a station in Copper Harbor.

The website reports user-submitted data on gas prices at specific stations.

Email Melissa Anders at manders@mlive.com. Follow her on Twitter: @MelissaDAnders.