Yes, you can modify a Route Collection by clicking the edit icon on your My Collections page. This allows you to add, delete and reorder the routes in the collection, as well as changing any notes you've added.
Not sure - I'm still a beginner here!
Is it possible to add or delete routes to an existing collection?
It looks like all the routes are private so that's why they're not showing. You can change them on the My Routes page. I'd recommend creating a new route collection after making the routes public as the other one may be cached in your browser.
I just created a collection of 6 routes and want to see them on a map but all I get is a black page.How can I view a map with the routes plotted on please?