You have to drive 500 miles from Monday to Sunday of the same work week. In Kilometers that would be 804. Nothing else to do. They say that if you got another accomplishment during that week you will have to wait another week before completing another accomplishment, they don't say which accomplishments do this. Did you get other accomplishments during the same week?
Here is a link to the wiki http://www.waze.com/wiki/index.php/Map_Editing_-_select_map_editor?title=Points#Bonus_points_and_road_goodies