Because of the operation distractions created by large in-vehicle touch screens, it is necessary to explore the influence of the locations at which clicking and sliding gestures are performed on driving safety and operation performance. This study conducted two experiments to identify an easy operation area. In experiment 1, the influence of control size and control position on click offsets was discussed. The results showed that click offsets increased with increasing control size. Click offsets were larger at positions blocked by a driver's arm and that were far away from drivers. The click accuracy equation was fitted for different hot zone sizes. Experiment 2 focused on identifying easy sliding ranges. The results revealed sliding areas for 20%, 50%, and 80% of users under different sliding directions and positions. This study identified easy and difficult areas for users to operate large in-vehicle touch screens, providing theoretical guidance for display buttons arrangement.