Final answer:
Slow drivers disrupt the normal flow of traffic, which can impede traffic and create unsafe conditions, possibly leading to accidents and increased pollution due to idling vehicles.
Step-by-step explanation:
Drivers who go far slower than the normal flow of traffic can indeed cause a great hazard. They often impede the flow of traffic, or create unsafe conditions that can lead to accidents or road rage.
For example, as vehicles speed through an intersection without regard to the posted speed limit, a traffic signal would be required to make them slow down, ensuring they cannot speed through. Similarly, when driving behavior, such as going significantly below the speed limit, disrupts the normal traffic pace, it can lead to congestion, increased pollution from idling vehicles, and elevated risks of collisions.