Route Names in a Trip Planner session take their names from the name of the Trip Planner session. If you change the Trip name halfway through your planning only the and-on routes have the new name.
This is very inconvenient and causes issues within Trip Planner, especially if you change the name outside of the Trip Planner.
I believe that all Routes in a Trip Planner session should be named for the root-name of the Trip + the Date, no matter how many times one changes the Trip Name.