The phrase "crawling with people" may be a bit too colloquial for some writing contexts. There are many alternative expressions that convey similar meanings while adding variety. You could use "swarming with people," "teeming with people," or "buzzing with people" to give the same impression of a crowded place. More formal synonyms include "bristling with people," "overrun with people," or "crowded with people." For a slightly more negative connotation, consider "infested with people" or "overpopulated with people." These alternative expressions can help add depth to your writing and capture the nuances of a crowded location.