First, remember not to run across the street trying to grab a taxi first when you are well aware that there has been someone waiting for that same taxi before you. This calls to mind the scene from Planes, Trains, and Automobiles where both main characters race down the street for the one available cab. You should wait your turn. If the weather is bad, you might want to share with a stranger one of the scarce taxis. When this occurs each of you will pay their own separate share of the fare.
When you are sharing a cab with a friend and are going in identical directions, the first person to get out of the taxi should chip in half of what the full fare will likely be including a tip. They shouldn’t try to play the part of the big spender by whipping out a $5 bill for a $2 ride. The person that is remaining for the rest of the trip should accept the cash. Trying to turn away the money at the last minute, although it seems like it’s a nice thing to do, it creates a feeling that the person is obliged to return the favor at some later date. Since you made an agreement to share the taxi you should both honor it by paying for your fair portion. This recognizes that you were both responsible for the cab and neither one of you was treating the other. If you want to take care of the full fare as a treat for your friend then you should do so before you get into the taxi and before the other person thinks that you will be sharing it. You can simply say “Can I drop you?” This means that regardless of whose location is closer, the other person will be dropped off first and you will be dropped off last and will take care of the full fare at your destination.
If there is a man and a woman taking a taxi together and the man gets to the door before the woman he should open the door for her. Though it is proper courtesy for a woman to get into the taxi or the back of a car first, this can be bent if the woman is wearing a skirt that is long or clothes that are hard to move around in she should get in last so she won’t have to slide all the way across the back seat. As far as directions go the man is usually the one to give them, but if a woman is the one who knows where both are going then she should simply tell the driver directly.
The Taxi Driver: Sometimes you will have a taxi driver that wants to chat with you when you don’t want to. Simply say “I’d rather not talk now.” If they keep rattling on about whatever it is they just have to talk about you can follow up in a more persuasive tone with a “I’m taking this taxi so that I can have some quiet time and relax.” A taxi driver that has his radio on at an uncomfortable level can be asked to turn it quieter, just not off completely. This is basically his place of business and if he likes to here music at his business, so be it. Tip the taxi driver 15-20% unless he doesn’t follow the route you asked. At this point leaving no tip is your only recourse as their is no one to complain to in the moment.