Coming from Paris, I know that dealing with cab companies is a huge pain. And that's why there are a lot of initiatives that try to deal with what we call "la petite remise" which are private cars. The legislation is far less strict with them. The only problem is that up to now, there's a numerus clausus for them. But it is said that they're going to increase this number in the few next years, so it's still a big opportunity.
Still, taxi drivers hold a strong negociation power against governement: they're strongly unionized and they don't hesitate blocking trafic in case a new law might harm their business...