TaxiRate it's a fare calculator for taxi routes around Barcelona, at urban or between city destinations.
Put your location and your destination, plus your supplements: Luggage, airport, train station, etc. and it will give you the cost of the route. You'll be able to see the best route on the map and a turn-by-turn list.
To give you more precision, the fares are calculate with real time traffic affluence of the streets.
The fares are based on the official rates of the Instituto Metropolitano del Taxi 2012.