Don't get ripped off by taxi drivers at Heathrow

Last week I attended a conference in the Heathrow area. Two separate Americans told me of being ripped off by taxi drivers:

1) Two women were charged 35 pounds to travel the 4 miles from Heathrow Airport to the Quality Hotel. They were not pleased to find out that they could have taken the Hotel Hoppa bus for 4 pounds each.

2) A guy was charged 55 pounds to travel to the Slough/Windsor Marriot hotel, which also is on a Hotel Hoppa route.

I can kinda see the reason why this happens. Taxi drivers wait in a line at Heathrow and expect passengers to be headed into London (which would cost 35 pounds or more). But, when they are asked to drive a few miles to a local hotel, an unscrupulous taxi driver may then try to get the same amount of money, except without the drive into London.

Note I'm not talking here about the "black cab" London Taxi drivers, who use meters and are (I find) generally very honest. But the drivers at Heathrow who do this seem to be locals, not using meters, as far as I can tell by listening to these stories from people who were ripped off.

The lesson seems to be to either (a) just use the Hotel Hoppa bus if you're going to an airport hotel, or (b) negotiate a fare up-front. Paying the equivalent of 100 dollars for a 3 mile taxi ride really is just crazy.