Having a new driver in the car saying things like "Mom, you didn't come to a full stop" or "what is the speed limit here?" makes you take a look at how you are driving. And it's amazing how informal you can get after 30 years of driving. I'm surprised at the number of roads I don't know the speed limit for - I just drive the speed that seems appropriate (which luckily is usually pretty close to the speed limit, but not always). I think I learned the speed limit once and simply incorporated that knowledge into my driving habits... but I'm not sure. Then there's all the nearly-full stops, where I could easily get completely stopped if I needed to but that aren't actually complete stops. Or stopping where I can see both ways, instead of stopping at the stop sign and then moving forward to where I can see. Or forgetting to look both ways when I cross a train track with the arms and lights that are supposed to warn me about a train - but could fail.
Even more surprising is the number of things that most competent drivers do that aren't actually legal. The most common one is creating a right-turn lane out of the shoulder, in order to bypass the cars stopped at a stop light. I found out the hard way that it is legal to pull up to the right of ONE car and turn, but if you pass a second car on the way to the corner, that is passing on the right and illegal. And don't even think about getting one tire off the pavement onto the shoulder - that gets expensive if a policeman catches you. Then there are all the rolling stops that allow the driver to slip into the flow of traffic on a busy street, where coming to a full stop would create a long wait; hopefully, the driver has gotten a good look both directions, but even so, it is illegal.
And then there are the things that sound illegal but aren't. According to driver's ed, there are lots of rules about pulling a U-turn which pretty much come down to "only if there is no one around to see it". But I see lots of drivers turning south onto N. 7th from Baxter Lane, because they aren't allowed to turn north, then pulling a U-turn around the median at the next stop light and heading north. I called the police department, and an officer said that in Montana, U-turns are legal as long as there is no sign prohibiting them and you don't impede traffic. So the N. 7th U-turns are legal as long as you can make the full turn without backing and filling, and someone turning right onto N. 7th doesn't hit you. U-turns are even legal on Main Street as long as it doesn't impede traffic.
What else should I have asked the officer about when I talked to him? What other habits are going to get me in trouble some day?