When layoffs are rife, a worker who goes on vacation must wonder whether his job will be there when he gets back. Nonetheless, a poll conducted for Xylo Inc. by Wirthlin Worldwide finds workers determined to get away. In all, 77 percent of workers polled said they plan to take time off this year, up from 70 percent in last year's poll. They won't just vegetate: 72 percent expect to travel, vs. 64 percent a year ago. Married non-parents are the cohort most likely to plan a vacation (87 percent) and to travel (84 percent), edging married parents in both respects (83 percent planning to vacation, 76 percent to travel). Footloose though they are, single non-parents are less likely to vacation (70 percent) or to travel (67 percent). But single parents are even less likely to plan a vacation (65 percent) or a vacation trip (60 percent). The chart below gives an idea of what vacationers will do in their days away from the salt mines. And how will these people get to their vacation destinations? In a Gourmet poll, 67 percent of respondents who plan to go on a leisure trip said they'll do so by airplane. Just 5 percent said they've changed their mode of travel due to a post-Sept. 11 fear of flying.