There are several synonyms that can be used instead of the phrase "in transit to." These include "en route to," "on the way to," "journeying to," "traveling to," "moving towards," "headed for," and "bound for." All of these phrases convey the same idea of something or someone being on their way to a specific destination. Whether it's a package being shipped or a person traveling to a new city, using one of these alternatives can add variety to your writing while still getting the desired message across.