Round Trip Travel Time

I have a route which is out and back, recorded as a line on my map.

When I use 'Travel Time', it shows me the one-way time from trailhead to summit.

Is there a way to show the round-trip time, from trailhead to summit and then back to trailhead?

Many of our climbing and ski routes are 'up-and-down' - we ascend and descend the same path. 

Marc showed me the solution: extend the route all the way back to the trailhead.

OK I can do that.  But it seems to me this would be a common use case that deserves a better solution.

Feature request: in 'Travel Plan', have a 'Round Trip' checkbox that calculates the back-and-forth time.