If you ask anyone you know whether they think they're a good driver or not, you're likely to get one answer. It'll usually be variations on the theme of: "Yes, of course I am you dim-witted peasant."

But therein lies the problem. Just like the Emperor in the classic and utterly brilliant original Star Wars trilogy, people's over-confidence is their weakness. The other day I was minding my own business on the M4, almost fully past a joining slip road in the left hand lane, when I heard a horn.

The road was quiet and everything had seemed serene, so I was nonplussed as to the drama. I looked in my mirrors to see a woman who shall remain nameless - mainly because I don't know who she was - in a black Peugeot gesticulating in my direction while pulling off the slip road.

As she then overtook the Citroen DS5 I had on cruise control, she continued to flail around, apparently explaining that I should have got out of her way when she was trying to join the motorway.

Now it's hard to offer a rebuttal detailing the intricacies of someone's errors in a situation like this. But I do my best to learn and abide by the rules of the road because then I can avoid getting something wrong and risking a crash, like this delicate flower in the Peugeot.

Check in any official copy of the Highway Code and it'll tell you that when you're joining a motorway you must give priority to traffic already on the carriageway. But the reality is that a lot of left-lane users get out of the way of joining traffic just because they want to avoid a potential accident. The situation has got so bad that people joining the carriageway seem to think they've got the right of way and keep coming regardless.

But wait a tyre-squealing minute here. That's not just putting the cart before the horse; that's transplanting the horse's face onto its own backside and teleporting the cart to a different dimension. Traffic on slip roads joining a main road or motorway has a responsibility to find a gap and get into it safely. It's nobody else's responsibility to create a gap for them or get out of the way. And that's the law.

If the Woman in Black (well, a black 206 CC) had ploughed into the side of my poor, innocent DS5 she'd have been up before a magistrate faster than she could have read the paragraph of the Highway Code that proves her wrong. But she drove off convinced of her own perfection. Like so many people, she's probably never even picked the Code up. How the heck they can believe so furiously that they're always in the right is way beyond me.

I don't know about you but I find this sort of thing massively frustrating. Why can't people just read it? It's even written in bite-size chunks that are easy and fast to take in. If we all set to it and spread it out over a few days, in no time we'd all have learned most of the actual laws behind safe driving and I'd be willing to bet my extremely sentimentally valuable old pig soft toy that we'd have a lot fewer conflicts and near-misses on the road. And if that happened, drivers in general would be a lot more smiley.

But since I can't hope to explain this the next time someone does something so utterly wrong on the road that it makes me want to pull my own teeth out, I think I might just make a small placard that I can hold up at offenders. It'll say something like: "Listen fool, if you don't immediately pick up a copy of the Highway Code, read it and write me a lengthy thesis/apology focusing on why you were in the wrong even before shouting your ill-informed abuse at me, I'm going to find the Jumbo Extra-Large-Print Hardback Edition Highway Code for the Chronically Myopic and Terminally Stupid and whack you around the face with it"

No, wait. That's still far too long for a placard. At the font size I'd have to use I'd need a trailer to carry it, and that's not going to help at all. Although there's nothing in the Code about not being allowed to activate your cruise control and shimmy out of the boot to grab a mildly abusive placard out of your trailer. Probably.