In fact the running mile is even worse than £2, although it's a mixed picture, and explains why they want to simplify it. So it's one of these stepped tariff structures, and not just a single step, but several. Thus:
Flag is £4.00, which covers 2/12ths of a mile
Then for the rest of the first mile (ie 10/12ths of a mile

) it's £2.40 for the running mile (or the part thereof).
So in total the first mile clocks £6.00
It's then £1.60 per mile for miles two and three
Then £1.50 per mile for miles four and five
Then £2 per mile for any distance thereafter
So no wonder they want to simplify it - I mean, one of the increments is per 2/15ths of a mile
And that's just the day rate
So the rate isn't too bad for the first mile or so, but after that...