I had to get a taxi home this evening, because the trains weren't running. Most of the journey is along a motorway, for almost all the motorway journey the driver was holding his mobile phone and talking into it, barely looking up at the road (and it was busy, dark and raining). I was really scared for my safety but didn't dare ask him to stop as something about his manner seemed really on edge and I thought it might make things worse.
I asked him to stop at a shop a few minutes from my house, and handed him half the fare and said as I got out that this was because for most of the journey he was driving illegally and was really scared!
he followed me into the shop and was very threatening, but then eventually walked away. but then the shop assistants spotted him waiting outside, so they let me leave by the back of the shop so he couldn't follow me.
was I being unreasonable to have only paid half the £20 fare? He seemed totally outraged that him driving illegally should have any impact on me paying him...
(I have also reported him to the police, but apparently they can only prosecute if a policeman sees the person talking into the phone, so that will come to nothing.)