Simonb wrote:
Here's an idea: take down the details of any taxi driving dangerously and
report them (anonymously if necessary) to your local council regardless of
whether you are a passenger or not.

That works on London Black Cabs, if one cuts you up or whatever, shout
their number (it should be clear on the plate on the rear of the cab) at
them, repeat it a few times if necessary and threaten to report them.
They back off so fast it's funny. Because to a licensed cabbie it's not
funny. They only need a few unconnected complaints (even if they're not
upheld) over the course of a few years and things can get messy when
they renew their registration.