Pretty sure Hackney Carriages in London did this from the 17th Century right up to 1907. "Raining Guv'ner, that'll be double the price"
So the City Of London introduced regulations, taxi meters and fixed fare tables.
"Yeah, we're not a Taxi company, we're on the side of the consumer against these nasty taxi companies, we don't need to comply with the pricing regulations, supply and demand"