Because I simplify the public transport network it's not only the travel between the order pairs. I removed all intermediate stops so the travel time between the order pairs is much shorter than the real travel time of the trip. So I use the restricted time windows to model the real travel time. The picture shows the route in reality with a lot of deviations, so when I model only the first and the last stop I will create a shorter route on the direct connection.
A possibility would be to model all intermediate stops but this would take a lot of effort, and I had to put a lot more data in the model.
after a long time, I have done some further work on the problem. The approach with calculating the service time from the wait time works.
So you can do some scenario with different values for the MaxViolationTime. This can give some hints where you have bad connections between trips (Bus A arrives at 12:01 at Stop A, Bus B leaves at 12:00 at Stop A) or where you can create better connection between trips by extending the time between trips.
At the end you will probably have a lower number of vehicles or a better vehicle utilisation.
If someone is interested I can explain the procedure more in detail.