For everyone out there that has either had to follow someone in a car or lead someone in a car to a destination, I am going to teach you the rules of tandem driving. They are not difficult. There are not many of them. And if followed by both parties may actually get you places faster than if you were driving one car.
Rule #1: Do not lose your follower. It sounds simple and almost self-explanatory, but you would be surprised how often this rule is violated. It is the number one reason people get lost when tandem driving. The infraction can be as simple as going through a very stale green light when the following car is sufficiently far behind you that it will hit the changing yellow light. Or even not waiting a turn at a full four way stop sign and putting two cars between you and the following car. (If you wait one turn, you would only have one car in between, which is much more easily overcome at a later time.) You may also forget that the following driver is not an aggressive driver, and so will not drive as fast as you. This can cause problems on the highway with merging cars.
Rule #2: Do not lose the leader. Of course, the converse is true for the driver following. How could it not be? If you notice that a light is stale green, and you think the leader will go through the intersection, you better close the gap before you end up running a red light. On the highway you have to keep at most three car lengths behind only. You are not a spy. There is no need to hang back when following. If by chance cars end up between you and the leader, you must try to pass them. Preferably on a long stretch where there are no exits for which you might need to scramble back into the exit lane. I would suggest the benefit of drafting behind the leader car, but that would imply driving rather fast, which I cannot advocate.
Rule #3: Use tandem driving to your advantage. This is the most underused and forgotten benefit of tandem driving. There certainly are many drawbacks to tandem driving, especially when one driver does not know how to get to the destination. However, there is one significant benefit. There will be times when you are driving on a multilane road and you will need to change lanes for an exit ramp, a turn, a faster lane, whatever. If the road is busy, switching lanes is easy for one car. But with two cars you risk losing the following car is they cannot change lanes as easily. If, however, the leading car puts on the turn signal to indicate the need to change lanes, the following car can change lanes first. Then the following car can slow down just enough to create room for the leading car to change lanes right in front of it. This is especially helpful when there are a lot of cars on the road.
Rule #4: Deal with speed demons. A very common occurrence while tandem driving is that cars will interpose themselves between you as they change lanes to drive faster. Often times this is because you are the faster drivers in the faster lane. However, because the distance between cars is also farther, an interposing car will only lengthen that distance, making it harder for one car to follow the other. In order to close this gap, the leading car needs to slow enough to cause the interposing speeding car to change lanes to a faster lane. The converse is not true with slow drivers—following cars should not tailgate slow drivers to make them change lanes. You simply pass them when you get to a long stretch of road. Leader cars should also notice when a slow car has interposed itself behind them and change lanes to allow the following car to close the gap.
Rule#5: Sometimes you just have to pull over. The final rule. Sometimes you do lose your following car at a red light or an awkward left turn or exit from a parking lot. You should pull over if you can to let your tandem partner catch up.
You might say that you could always just call each other and discuss upcoming turns and exits. (On speaker phone, of course…) Or just use GPS. And I would say that takes the fun out of both driving and tandem driving.