Traffic congestion refers to the situation where traffic becomes heavily congested or slowed down, leading to delays for motorists. There are several synonyms for 'traffic congestion', which can be used to describe this situation in different ways. One commonly used alternative is 'traffic jam,' which refers to a situation where there is a long line of cars that are moving very slowly or completely stopped. Another synonym that is used is 'gridlock,' which refers to a severe traffic jam where cars can hardly move. Other synonyms include 'traffic slowdown,' 'roadblock,' 'bottleneck,' 'snarl-up,' and 'traffic tie-up.' These synonyms are often used in traffic reports or news stories to describe the current situation on the roads.