When you plan a trip using Road Trip Maps, you can now update some of your vehicle specs without starting a new trip. When you update the details for the vehicle you are driving, the trip will then update according to those changes.
The options you select in the initial set-up are used to build the recommendations for your trip. For example, if you chose RV or Trailer as your vehicle selection, campgrounds will be chosen that can accommodate RVs/Trailers, leaving out options for tent only, hike-in access, etc. You can change those filters after the trip is built, if you like, or you can go into the trip settings and change your vehicle if you so choose.
From the app, go into the trip you'd like to update and select the 3 dots in the top right corner. From there, select "Edit Trip Settings" and then "Vehicle Details" to change whichever specifics you'd like. From there, you will have the option to replace or lock-in campgrounds that were initially recommended if you chose to build a recommended trip during trip creation.
Your trip will then update accordingly.