DRIVING SUPPORT APPARATUS, DRIVING SUPPORT METHOD, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

A driving support apparatus includes a surrounding sensor which acquires surrounding information, and a control unit which executes driving support control when a execution condition is satisfied. The control unit performs overwrite processing or retention processing based on whether or not a specific condition is satisfied. The specific condition is satisfied when the number of types of directions other than a straight direction included in permitted travel directions of a first road arrow marking detected at a first time point is less than the number of types of directions other than a straight direction included in the permitted travel directions included in second road arrow information already stored in a storage device at the first time point. The control unit then determines whether or not the execution condition is satisfied at the first time point based on the overwritten or retained road arrow information.