Help!: Cannot edit/remove part of a route

2 problems here:

 1) As I build maps, the tool sometimes takes liberties when I am moving along roads. Sometimes it doubles back, goes way out, and then comes back rather than taking the simpler shorter correct route. I don't always catch this as sometimes I am in a hurry. So that leads to #2

 2) I now have a route built, that I cannot edit. The route has about one mile of extra stuff added in from #1, and I cannot remove it, regardless of what I do. Any attempt to edit the route just makes it longer. I have a stretch of about 1 mile that I just want to remove. I see no way to do it. If I click the Undo button, the tool goes to the end of my route and removes from there.

 I am using the new mapping tool.

 Any help would be appreciated.