I have followed the directions on Google Maps to create a map with a set of directions on as a layer. The advice I followed was Here
An example of what this looks like in the creation tool is:
and I can "preview" the map like so: https://drive.google.com/open?id=1Owtp4cJZOX8dvnaZ9foH8LhlqwJ97Z7O&usp=sharing (should now be a public link)
But what I can't seem to work out is how to actually use those directions with the normal directions provided by google where I can route plan and get timings/distances etc.