Motor taxis and horse drawn taxis are allowed to go into the city centre to drop of and pick up fares.
Last time I visited Bruges in May we had a mini van which dropped us off and picked us up right in the main square. There was a time when they used to use a drop off point on the outskirts but that seems to be in the past now, .... Neil.
In July we were bussed for free to the nearby town at the port (which is a long way from bruges and town)We were dropped off at the train station which has frequent services into Bruges for 7 eruos (i think) or you could pick up a taxi into bruges (30mins) for 32 eruos. The ship excursions were astronomic and poor value into bruges as it is a small town easily enjoyed on foot and there are canal trips going from loads of laces @ 6 euros each.