I'm new to Cycle Travel and as yet I haven't spotted how to reverse a track. What I'd do as a work-around is to download the track and import it into Garmin Basecamp or Garmin Mapsource and 'invert' (aka reverse it) it that way.

+1. I was about to make this suggestion as well.

Has this been address? I’m new to the platform and have used Strava, RWGPS, and Komoot. Love the planning but seems glaring that you can’t reverse direction? I’m exporting to komoot and reversing the direction there. Otherwise this is the best route planner I’ve come across (excluding brouter) 

Yes - there’s a little orange reverse button on the left. (It doesn’t currently show up on the mobile view - that’s on the way!)

I think the reverse button merely swaps start / destination and not clockwise / anticlockwise.

I used Mapyx Quo to reverse the route produced.

Reversing a circular route is a bit more complicated because of the way cycle.travel works under the hood. But you can probably do it by adding via points halfway along the outward journey and halfway along the return journey, then clicking reverse. If that doesn’t work then let me know what your start/end points are and I can look into it more closely.

Does the route reversal simply go back the exact way you came, perhaps with allowances for one way streets? 

I ask because my route westwards last week led me down a 14% hill, which is scary enough with blind corners downhill, but none the less fun. On the other hand, if I wanted to retrace the journey, I would certainly work around that stretch. It's easy enough to do this by hand, so to say, but if I ask for the route to be reversed, it suggests I cycle straight up this incline, which I don't think I could physically manage, and certainly not with panniers. 

When you reverse a route, it calculates a new route with the via points in reverse order. So if you’d originally calculated ABCD, reversing it will give you DCBA.

It does look at the climb anew: for example, on https://cycle.travel/map?from=Gloucester&to=Chalford,Gloucestershire, the southbound route is more circuitous to avoid the steep climb of the Cotswold escarpment, whereas going northbound it’s happier to take the steep descent. Climb/elevation calculations are a dark art though and one I’m constantly refining!

That example is very impressive. Also, tracing the southwards route led me to discover the best place name in Britain - Woefuldane Bottom, outside Minchinhampton.