When you select 'Go to Song Radio' from a track menu, and hit play, if that particular track is already playing it would be a great user experience if it started the radio seamlessly.
So instead of starting the track again it just continues but the playlist has switched over to the radio. Could be extended to artist etc too, and would allow you to switch context without breaking the flow :)
Updated on 2019-01-22
Your idea was submitted a while ago and unfortunately didn't receive the amount of kudos needed to stay active in the ideas board (100 Kudos per year).
In order to keep the Ideas Exchange clearer I'll close this idea for now, but this doesn't mean Spotify rejected this idea.
If you think this is an idea which needs to be implemented, you're welcome to post it in slightly different again :)
Have a nice day!