For readers who tried to get gas availability information on the basis of information about "travel hotlines" in the Sunday Travel section of July 8 and may have been confused, here is a further advisory

Though the Howard Johnson chain does, as an official reported, have a "gasoline information number" (800-654-2000), it does not provide Aaa club numbers. In addition, there are only about 15 tollfree 800 numbers on the list and a recent spot check indicated that a few may be out of service.

The article also gave a number (800-555-1212) that was designated to provide the correct 800 number to call for information about gas availability in any state that has set up such numbers. Unfortunately, few such toll-free hot-lines are now available for out-of-state callers. In most instances, the most dependable way to get current gas information (unless you belong to a motor club) is to call a state's travel office after you drive into the state.

In the same edition, there was one incorrect figure in the article about driving from Los Angeles to Miami. The "cost per mile" for gasoline used by the writer should have been listed as approximately 4.6 cents, instead of 21.4 cents.