The Travel Industry Association of America is out with its annual summer vacation forecast.

It shows plans for leisure travel this summer are up 3.2 percent, the biggest increase in four years.

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Summer Travel Forecast: Busy, Crowded

"For the first time in years, the summer travel season will start off with a bang and we expect it to stay strong through August," said Dr. Suzanne Cook, TIAA's senior vice president of research.

Americans will take more than 334 million trips during June, July and August 2004.

The TIAA defines a "trip" as one person traveling at least 50 miles from home.

The survey shows 73 percent of summer vacationers are planning to visit a beach or a lake.

Nearly one-third plan to visit a theme park.

The TIAA survey shows Florida is the destination of 38 percent of respondents, ahead of second-place California.

Here's the top 10 list of places to visit this summer:

• Florida -- 38 percent
• California -- 29 percent
• Hawaii -- 16 percent
• New York -- 15 percent
• Colorado -- 12 percent
• Texas -- 11 percent
• Nevada -- 9 percent
• Washington, D.C. -- 5 percent
• Virginia -- 5 percent
• Alaska -- 5 percent

The dramatic shift in travel trends over the past few years, such as Americans taking more driving vacations, staying closer-to-home and visiting more rural destinations, will still be prevalent this summer but there are signs the trends are softening.

Air travel is expected to increase 5 percent this summer, primarily due to leisure travelers, compared to a 3 percent increase in auto travel.

RV travel is likely to remain very strong this summer.

Americans expect to stay away an average of 7.6 nights on their longest pleasure trip, down slightly from last year.

Travelers plan on spending an average of $1,101 on their longest pleasure trip this summer, up 4.4 percent from summer 2003.

Here are a few more highlights from the TIAA's summer travel study:

• Many trips will include children this summer, with 38 percent of travelers taking kids on their longest trip. Six percent will include a grandchild.
• Traveling with one's spouse is also popular (58 percent), as is traveling with other family members (20 percent) and traveling with friends (14 percent). Seven percent will travel with their parents and 6 percent will travel alone.
• Visiting friends and relatives (77 percent), going to a beach or lake (73 percent) and visiting small towns or rural areas (65 percent) are the top three most popular summer activities.
• Nearly one-third (32 percent) of summer travelers say they will go to theme parks, while 26 percent intend to go to a gambling casino. Nineteen percent of travelers plan to use an RV, while 18 percent intend to enjoy an all-inclusive resort. Ten percent say they plan to take a cruise.