Nearly half of all Americans will be traveling away from home on vacation this summer. More of them plan to vacation in the Midwest or near the Great Lakes than ever before, and July is increasingly their summer vacation month of choice.

Those were some of the findings of the "1988 Summer Vacation Travel Forecast" report compiled by the non-profit travel research U.S. Travel Data Center. The report, based on phone interviews with 6,000 randomly selected U.S. adults, predicts 113 million Americans will travel away from home this summer, logging 255 billion miles.The report indicates the Midwest and Great Lakes regions will generate the greatest increase in vacationers this summer, but the Southeast is still the most popular U.S. destination. Despite the weakness of the dollar, 13.4 million Americans will head for foreign destinations with trips to Canada or Mexico up by about 9 percent and trips to all overseas destinations up overall by 3 percent, the center predicts.

This year, July will become the most popular American vacation month, surpassing August for the first time and reflecting a three-year trend. The Center also predicts cities will edge out ocean beaches as the most preferred type of destination and 83 percent of summer's travelers will reach their destination by auto, truck or recreational vehicle.