I have street network for a city. I picked two points as stops for route analysis on a perfect grid street system. The shortest path between them is 185 seconds(only one right turn with penalty of 10 seconds). But it is choosing the path with 225 seconds (three right turn of 10 seconds of penalty each and two left turn of 20 seconds of penalty). Without any turn penalty the fastest route have travel time of 175 seconds.
I am confused, as the route solver is choosing the route with greater time travel rather than with lower time travel. Do you have idea what might be wrong with this?
I wonder if you have the settings wrong; be sure you are minimizing drive time.
Also, 10 and 20 seconds are huge turn penalties; you may want to re-visit the amount. Personally I'd do 10%- 20% of what you list.