What term describes the situation when large numbers of vehicles are moving on roads at the same time, causing traffic jams?

The term that describes the situation when large numbers of vehicles are moving on roads at the same time, leading to traffic jams, is congestion. Congestion occurs when the demand for road space exceeds the available capacity, causing delays and slowing the movement of traffic. This phenomenon can arise in various scenarios, such as during rush hours when many commuters are traveling simultaneously or during events that attract large crowds.

The other choices do not accurately capture this specific scenario. An accident refers to an unexpected event, often resulting in damage or injury, but does not inherently involve the overall traffic scenario characterized by congestion. Overcrowding typically describes physical spaces being filled beyond capacity but is not specific to roadways or vehicle movement. Interference suggests some disturbance or obstruction but does not effectively convey the broader concept of multiple vehicles contributing to delayed traffic conditions. Thus, congestion is the most appropriate term for this situation.