Why are some of the trips of the OD matrix not assigned?

Please check the following points:
- Is the evaluation period long enough to catch all of them? If the simulation runs for e.g. 3600 seconds and you do aggregate at the end of the same period, there will almost certainly be vehicles not yet arrived at their destination parking lot.
- Are there errors in the network topology reported to the messages file? You might find out that some vehicles cannot reach their destination because there aren't any possible routes between their origin and their destination.
- Make sure that after a modification to the network topology you delete the *.bew and *.weg files before running the simulation again.