Taxi Ettiquette

Okay, this post has been a long time coming. Several weeks ago we took a cab to downtown Columbia to see the battle of the bands at the Eastside Tavern. So, the cabbie picked us up and started driving down the road. He decided not to turn on a street and get on the highway...which was the fastest way. I didn't say anything at that point, but I was pissed. So, a mile up the road out of our way is another chance to get on the highway. I figured he was going to screw us a little by taking the back way to get to the highway. So, I expected him to take his next chance and get on 70. As we neared the intersection, it was apparant that he had no intention of getting on the highway at all. Instead, it looked like he was going to take us 10 minutes out of our way to get to where we were going. At this point I was really pissed and exclaimed "Dude, take 70!" He almost missed his chance to take the highway. After that, I wasn't going to take any chances, so I told him exactly what route I wanted to take to get to the bar (which is the shortest/fastest). The point of all this is....has anyone else been in a situation like that and, if so, what is the proper ettiquette? I was outraged that he was taking us for idiots that don't know where we are going. So, do you call the dispatcher on him? Not tip him? Yell at him for taking advantage of you? Is it appropriate to tell the driver that he's taking a shitty route? I ended up letting him keep the change, which ended up being about a buck. Hopefully he got the hint, but in retrospect I wish I would've been more vocal about the poor treatment. We used another cab company to get back home that was both cheaper and faster.