Need the ability to assign freight carriers to delivery - block grayed out - trip already created

Hi Everyone:

Due to a business process, we are creating the delivery and the trip at the same time.  We are planning by delivery; we are not actually using trips, except for basic needs.  The issue we are encountering if you create the delivery, and then create the Trip directly after, you cannot add the carrier information on the delivery.  We need the ability to create the delivery, trip, and then assign the carrier to the trip.

 

Has anyone done this? We have tried a forms personalization to enable the filed on the form, we are having issues because the Trip and the delivery are conflicting with one another since they both access the carrier table.