Best not to mention the trams in Edinburgh. They finally finished the line (all the way from the airport to the port in Leith) but it cost waaay more than planned, had to be done in two phases and was a massive ballache during the construction.
That said, it is an absolute win for public transport in the city but it did knock the confidence of residents. Mostly down to the piss poor management of the project by the council.
Two pints prick!