Nearly 1.7 million Carolinians -- an increase of 3 percent from last year -- are expected to travel this Independence Day, the busiest weekend of the summer, according to AAA Carolinas.

Interstates will be crowded, with more than 510,600 South Carolinians and 1,042,000 North Carolinians expected to hit the road this weekend.

Many travelers will enjoy the benefits of a highway system that revolutionized the American vacation when on June 29, 1956, President Dwight D. Eisenhower signed the Federal Aid Highway Act giving birth to the nation's Interstate system.

For 50 years, Americans have enjoyed speedier travel to popular destinations, without having to encounter traffic lights or intersections.

Air travel has also come into its own. More than 95,530 North Carolinians and 46,800 South Carolinians will fly this weekend, an increase of nearly one percent from last year. Air fares are up 7 percent and car rental fees up 5 percent this year.

Gas prices have dropped slightly from Memorial Day, down three cents in both states to an average of $2.75 a gallon in North Carolina and $2.62 in South Carolina. However, gas prices are about 60 cents higher than this time last year.

Hotel rates are 10 percent higher for AAA-rated Three Diamond hotels at 20 top destinations compared to last year.

North Carolina motorists will find the least expensive gas in Wilmington at $2.726 a gallon of regular, unleaded, self-serve gasoline. Boone has the most expensive per-gallon price at $2.800.

South Carolina's least expensive gasoline can be found in Spartanburg at $2.572 per gallon. The most expensive is in Myrtle Beach at $2.677 a gallon.

"Vacation travel has changed dramatically in the past 50 years, and it will be obvious this holiday weekend -- the biggest vacation travel weekend of the summer," said David E. Parsons, CEO and president of AAA Carolinas. "Americans will be staying in roadside hotels and dining in restaurants spawned by the popularity of our national highway system."

At 50 years of age, however, North and South Carolina's highways are in trouble, according to AAA.

An extra $1 billion has been requested by Elizabeth Mabry, executive director of the South Carolina Department of Transportation. The extra funds are needed to pay for road construction and maintenance as well as other transportation projects.

South Carolina's 16 cents-per-gallon gas tax hasn't been increased since the 1980s and no longer meets transportation funding needs. Another $920 million over the next three years is needed in North Carolina for road building, maintenance and other needs.

The 2006 July Fourth holiday begins at 6 p.m. Monday and ends at midnight Tuesday.

Last year in North Carolina, 15 people died in 1,392 collisions during the July Fourth holiday period. There were 11 North Carolina highway deaths during the Independence Day holiday in 2004.

Seven motorists died on South Carolina roads, up one from 2004, according to the SC Department of Public Safety. Carolinians have picked their hot spot destinations for the holiday weekend. Forty-two percent said they plan to travel to cities, 29 percent plan to enjoy beaches and 12 percent plan to go to state or national parks.

As part of their ongoing holiday travel philosophy, South Carolina's Department of Transportation plans to have all lanes open to accommodate increased weekend traffic. Construction in North Carolina will be halted as well.

This weekend's drivers will have a much different travel experience than the first highway adventurers 50 years ago, paying $2.86 a gallon for gas compared to 22 cents a gallon in 1956.