Apologies, I've been snowed-under and didn't get a chance to look at this until the other day.
While there is no way to get the current road permanently displayed, if you tap the bottom of the screen while navigating to somewhere then it should display the current road, along with the Estimated Arrival Time, Distance to Destination and Time to Destination (which are already shown along the bottom). This appears as a kind of popup window which can be closed by clicking on the Close button (at the bottom) or disappears automatically after about 10 seconds.
Afraid this is the closest I could find to what you are looking for.