You can see a list of all routes that you've saved on your My Routes page. From here you can manage the list, including renaming any that you don't need.
To access your My Routes page, select My Routes from the Routes menu. You can also click the Manage Routes button on the My Routes tab on your personal home page.
Once on the My Routes page click the pencil icon to edit any details you provided when saving your route, including its name.
You can also rename a route by editing it and saving it again with a new name. This will rename the route you are editing (as long as you don't choose Save As New Route).
Once a route has been renamed, the new name will appear when anyone views the route. Changes to the route name on embedded maps may take up to 24 hours to take effect.