What effect does heavy congestion typically have on the average speed of traffic?

Heavy congestion generally leads to a significant decrease in the average speed of traffic. When roadways become congested, vehicles are packed closely together, often leading to stop-and-go conditions rather than smooth, free-flowing traffic. This inefficiency is primarily due to several factors, including reduced acceleration and deceleration capacity, as well as increased delays at intersections and stoplights.

As the congestion worsens, the average speed can drop precipitously. Drivers are forced to navigate more cautiously and deal with frequent interruptions, which further exacerbates the slow movement of traffic. Ultimately, the overall travel experience becomes frustrating and time-consuming for motorists due to these traffic conditions.

While extreme congestion can lead to completely stopped traffic, the typical effect characterized by heavy congestion is a marked decrease in average speed rather than a complete halt or no effect at all.