Cost Of Taxi Journey

[Barsel]

Next month I have a hospital appointment and the chances are, I might have to get a taxi to take me there.
I usually drive myself but am not able to at the moment and I was wondering how much it would cost me.
I've done the route on Goggle maps and it's about 10miles, but it will be 8am when I suppose the roads will be busy.
Do taxi's charge by the distance or how long it takes?
How much should I expect to pay?

[ladybirder]

Barry I was having a cataract removed so wouldn't be able to see to drive home, plus my age, perhaps had something to do with it.