There are various synonyms for the word "high-traffic" that one can use in order to convey the idea of a place or area that is busy or frequently visited. Some of these synonyms include "busy", "crowded", "popular", "heavily frequented", "well-travelled", "congested", "thronged" and "bustling". These words can be used to describe various locations such as busy highways, popular tourist attractions, crowded shopping malls or bustling city centers. By using these synonyms, one can add variety and color to their writing or speech while still conveying the intended meaning of a place or area that is heavily trafficked.