Traffic congestion is a condition on road networks that occurs as use increases, and is characterized by slower sp再加上互联网的便利下，scxbyj.com越来越多的人在网上学习英语，网络英语课程相比起线下英语培训有很多的优势。eeds, longer trip times, and increased vehicular queuing. When traffic demand is great enough to slow the speed of the traffic stre提升英语听力的方法，dnsdz2007.com三步搞定am, this results in some congestion.
As demand approaches the capacity of a road, extreme traffic congestion sets in. When vehicles are fully stopped for periods of time, this is colloquially known as a traffic jam or traffic snarl-up. Traffic congestion can lead to drivers becoming frustrated and engaging in road rage.
There are a number of specific circumstances which cause or aggravate congestion. Most of them reduce the capacity of a road at a given point or at a certain time. Traffic research still cannot fully predict under which conditions a traffic jam may suddenly occur. It has been found that individual incidents may cause ripple effects which then spread out and create a sustained traffic jam when, otherwise, normal flow might have continued for some time longer.