Gasoline prices have been falling in Iowa for weeks, but they’re still well above a year ago, so travel projections for the upcoming holiday weekend are down. Rose White, at Triple-A Iowa, says the motor club estimates 39-million Americans will travel at least 50 miles from home during the five-day Independence Day holiday.

White says that’s a 2.5% decline from the Fourth of July weekend last year. Of those traveling, nearly 84% will plan to travel by automobile, another eight-percent will fly to their destination and the remaining eight-percent will travel by other modes including rail, bus and watercraft.” Gas prices in Iowa were near four-dollars a gallon in May but have fallen to a current average around $3.56 a gallon. That’s well above the statewide average price from a year ago of $2.67.

White says in addition to the regular road hazards, Iowa motorists will need to keep a closer eye on the highway. “Roadways near major waterways in the Midwest may be impacted by flooding,” White says. “Before you leave, pack a detailed road map in your vehicle in case you need to select an alternative route.” Also, she suggests you store phone numbers or web addresses to the state road departments on your cell phone or PDA. If possible, White says to avoid driving at night since it’s hard to see flooded roadways in the dark. Do not drive across a flooded roadway, she says, but instead, dial 911 and report it.

“Keep in mind that today’s automobiles are equipped with many electrical systems and computers that may be damaged if exposed to flood waters,” White says. “Always keep your fuel tank at least half full at all times, just in case an unexpected detour is required.” While Iowa’s current statewide average for gas is $3.56 a gallon, the national average is $3.60.

The state’s all-time high was set in July of 2008 with $4.02 a gallon.