Tie-up and Traffic jam

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

Traffic jam and tie-up are semantically related. In some cases you can use "Traffic jam" instead a noun phrase "Tie-up".

Traffic jam noun - A number of vehicles blocking one another until they can scarcely move.

Tie-up and traffic jam are semantically related. Sometimes you can use "Tie-up" instead a noun phrase "Traffic jam".