Washington -- Travel in the United States will continue to grow next year but at a slower pace than this year, the Travel Industry Association of America (TIA) said yesterday.Domestic leisure travel volume will increase 2 percent next year over this year while international travel to the United States will rise 5.5 percent, according to TIA's Annual Travel Forecast. By comparison, domestic leisure travel will rise 4 percent this year over last year, and international travel will increase 7 percent.Domestic and international travelers will spend 4.4 percent more next year within the country than this year, for a total of $674 billion, TIA forecasts. Travel spending in the United States increased 7.8 percent this year over last year."The industry is holding strong but a number of indicators, such as vacillating consumer confidence, waning CEO confidence, and an expected sharp rise in energy costs are having an effect on consumer and business attitudes," said Suzanne Cook, TIA's senior vice president of research. "As a result, we're starting to see signs of a more cautious consumer when it comes to travel."I don't expect Americans to stop traveling," Cook added. "I simply think they will be more careful when it comes to making travel decisions."Domestic business travel is likely to be constrained in the final months of 2005 and the first quarter of 2006, according to TIA.Nonetheless, TIA expects the growth of domestic business travel to increase slightly next year over this year: 1.6 percent for 2006 compared with 1 percent this year.