Final answer:
A road sign at an intersection with an arrow indicates that you may only travel in the direction shown by the arrow. It can indicate left turn only, right turn only, straight ahead only, or no U-turn, depending on the sign's specific depiction.
Step-by-step explanation:
When encountering a road sign at an intersection indicating a direction with an arrow, it instructs you to travel only in the direction shown by the arrow. These road signs are critical for directing traffic and ensuring safety on the roads. Based on the description provided, if the sign shows an arrow pointing left, then the sign indicates left turn only. If it points to the right, then it's right turn only. A straight arrow would mean straight ahead only, and if it's showing a U-turn sign crossed out, it would mean no U-turn is allowed.
These signs help control the flow of traffic and enforce compliance with the posted speed limit at intersections. They provide a direct instruction, simplifying the directions into terms such as to the left, to the right, or straight ahead, which is the simplest way to show direction.