(Reuters) - Motorists will travel in record numbers for the Independence Day holiday this year, encouraged by cheaper gasoline, travel group AAA said on Tuesday.

The group said 35.5 million people will drive 50 miles or more away from home between July 3 and 8, up 4 percent from last year and the largest number in the last decade.

An additional 3.2 million will fly to their destinations over the holiday period, up 9 percent from a year ago, bringing the total number of vacationers to 42.3 million, a tie with the decade's record in 2007.

A gallon of gasoline will sell for $3.57 during the holiday, down about 3 percent from a year earlier, AAA said. The price forecast is based on the year's average gasoline prices through June 11. Gasoline prices peaked in early April this year, at an average $3.94 for regular gasoline.

The group expects no changes to airfare costs year-over-year.

The forecast, based on a survey of 50,000 U.S. households, said travelers are likely to take more days off to travel this year since Independence day will fall on a Wednesday.

(Reporting by Selam Gebrekidan; Editing by David Gregorio)