Final answer:
A road sign with an arrow typically indicates that the street is a one-way street, with traffic flow restricted to the direction of the arrow, which improves traffic flow and pedestrian safety.
Step-by-step explanation:
If you are trying to interpret a road sign that has an arrow, then this sign typically means that traffic goes one way on this street, or more commonly, this is a one-way street. The arrow is an indication of the direction in which vehicles are allowed to move. So, when you see a sign with an arrow pointing in a certain direction, it informs drivers that the traffic flow is restricted to that direction only.
It is not suggesting that only up and down arrows are allowed, as that does not pertain to traffic directionality. The intention behind such signage is to regulate traffic flow and improve pedestrian safety. By ensuring that all vehicles move in one direction, the risk of head-on collisions is reduced.
The overall traffic movement becomes more predictable, which is especially important in areas with heavy vehicle and foot traffic. Furthermore, it simplifies the crossing process for pedestrians who only have to check for traffic coming from one direction.