I like taxi. I think this is a good idea. I hope in my city also accept bitcoin. because everyday I use taxi.
I heard uber was considering the use of bitcoin, but I'm not sure. I don't really think it will work in a near future though because the fees are still to high, so paying a taxi, that normally is already expensive, will become even more expensive because you will be paying fees for the transaction. It would be much better for users to just pay with fiat.
For me, Bitcoin is not the cryptocurrency that will solve this problem. Because as of now, bitcoin is used as investment or something like stocks and its too volatile to use as daily transaction. I suggest another altcoin or token, the advantages are to promote their business and win customer's loyalty by giving them incentives who use tokens. It is proven in some services and I believe, it will be effective in transportation section.