Wiktionary
in route
a. (context somewhat nonstandard English) (alternative form of en route English)
Usage examples of "in route".
Venizelos hadn't had to tell him the change in route was going to put them behind schedule, either.
Critical re-supply efforts and materiel that were in route to the Middle East were now going to have to be shared while America built up to defend itself at home and to fight large major wars on two fronts.
Several times a day, mission or no mission, McGuire Air Force Base in New Jersey faxes weather bulletins to Suffolk Airbase for their use in route planning.