Does Zwift alert you when a lap is completed?

Is there any marker indicating when you’ve completed a “lap” of the route you selected, or does it just keep going?  This morning I selected a route based on the distance in the Routes section; it said it would be a certain distance, but I never could tell when I “finished” the lap. 

 

Most of the routes finish at the start/finish banner. To answer your question no there is not a onscreen indication that you are done.

 

Here are some helpful info on all the routes. https://zwiftinsider.com/route-details/