Taxis can be more economical than owning your own car in several ways. When you choose taxis or mass transit, you avoid car payments, insurance costs, and maintenance expenses. You don’t have the freedom to get into your own car and go on a moments notice, but on the other hand, you also don’t have to pay tolls or parking fees.
Buses and subways are much more economical than cabs, but aren’t as fast or prompt.
A taxi ride is definitely a lot less expensive than a drunk driving arrest.
When traveling to a different city, getting a cab would be much cheaper and more practical than renting a car, unless you had a lot of commuting to do while you were there.
One bonus to taxis is the colorful human beings that you get to meet who have chosen to become Cabbies. Not to stereotype, but I have met a few zany cabbies over the years. Some of them are better than a movie.