Rush hour and Tie-up

Rush hour noun - The times at the beginning and end of the working day when many people are traveling to or from work.

Tie-up and rush hour are semantically related. In some cases you can use "Tie-up" instead a noun phrase "Rush hour".

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

Rush hour and tie-up are semantically related. Sometimes you can use "Rush hour" instead a noun phrase "Tie-up".