In my experience on Android CT does not recalculate the route when I go off course - that is with maps already downloaded and internet access.

Personally, that is my preference. I normally use a dedicated GPS device and have the reroute feature disabled. 

If this is a problem for you, it should be a simple enough process to use the app to plot a new route to your destination or closest point on your original route (presuming you have Internet access).

In reality, the underlying maps are more than good enough to follow an imaginary route on the fly to get me to where I want to go or rejoin the original route. Note, I *think* the original route may disappear after a certain (long) time. Reloading the route will fix that.

Is this not the kind of thing that can be tested at home on a quick, short route, though? 

When it comes to tech in unfamiliar places I have always found it very beneficial and much less stressful to understand how the tech operates, especially in stress-testing situations - such as going off course. The best way for me to understand it is to test it live. 

Going off course and relying on tech can throw up some interesting situations.

Recalculating may involve using a different type of surface than originally specified (think gravel instead of paved).

That may be the difference between doing a U-turn to return to the original route and taking an alternative to rejoin it later. 

It may mean gradients being treated differently to get us back on track (perhaps the tech was avoiding that big hill that is now in front of us for a reason!). 

If relying on a distance/elevation countdown going off course can mess that up. Yesterday, while off course my countdown distance was getting longer and longer despite me getting closer and closer to my destination. 

Finally, tech attempting to recalculate a route as we move along off course can add to the power usage depleting the battery faster. 

I'm pretty sure a route recalculation feature is on the way for the CT app but for all the reasons above I suggest some good testing when it arrives. 

Many thanks, as you say testing is key.

I haven't previously re calculated, just headed back to the blue line at its nearest convenient spot.

Looking forward to understanding it better

Thanks again 

I'm pretty sure a route recalculation feature is on the way for the CT app

It is! The iPhone app currently offers manual recalculation – when you go off-course it flashes up a ‘Reroute’ button that you can tap. The Android app doesn’t yet. I’m looking at automatic recalculation though it might end up being a supporter feature (basically just in case an gone-off-route phone starts sending thousands of routing requests to the server…).