That’s actually something different 
and seems to be related to this question: Wrong distance between two waypoint or direction - #12 by lllaurent
Essentially the example you shows means:
Turn left onto B3. Then follow the road for 7.76km. From the beginning of the route, you traveled 8.09 km by then. Then you need to turn right on “Nincoper Straße” and follow the road for 9.42 km. Then you will reach the destination.