AUTOMOBILE EXPENSE-PER-MILE FIGURE rises, according to the American Automobile Assocation. The cost of owning and operating a car in 1988 will average 27.3 cents a mile, up 2.7 cents from last year. The estimate is based on a range of car sizes, each driven 15,000 miles a year and kept for four years. AAA ALSO SAID A FAMILY OF FOUR can expect to spend $170 a day for meals and lodging on auto vacations, plus $22 for 300 miles of daily travel. The total is up $14 a day from last year. THINKING OF GOING ON A SAFARI? A hot line to answer questions has been set up by Safariworld, a company that has been operating tours to East Africa since 1972. The number is 800-336-5500 or 800-366-0505, Monday through Friday, 9 a.m.-5:30 p.m., Eastern time. One popular tour, ``Safari Explorer,'' a 13-day trip to Kenya, starts at $2,728 per person, including air fare from and to New York. THAILAND HAD MORE VISITORS LAST YEAR. There were 3,482,857 arrivals, up more than 23 percent from the previous year. Bangkok was the most-visited city, but other areas of the country also shared in the activity generated by a year-long ``Visit Thailand'' campaign.