Forgive me for over-analyzing.. but don't most cabs have driver-controlled door locks nowadays?
You know, to prevent passengers from ditching without paying?
If so, how did this woman get out of the cab?

Was there a partition to protect the driver?

I agree, the cabbie ought to have exited off the highway if possible, but if that girl was wailing on the back of his head, what can you expect him to do?

I don't know if she deserved to get run over... but she sure as hell didn't need to start assulting a cab driver in a drunken fit.