Bottleneck and Traffic congestion

Bottleneck noun - A crowded mass (as of cars) that impedes or blocks movement.

Traffic congestion and bottleneck are semantically related In some cases you can use "Traffic congestion" instead a noun "Bottleneck".

Bottleneck and traffic congestion are semantically related in traffic tie-up topic. You can use "Bottleneck" instead a noun phrase "Traffic congestion".