I came here to study too, just forgot to leave, lol. Actually I did leave and then came back, who knows why? I've never really liked it round here!
Anyway, Canterbury is a small, heavily congested city. I do a fair amount of rural road driving too and there is zero chance of overtaking 90% of the time. Obviously the key is knowing the road well, your and your car's capabilities in those circumstances, then it can be done safely. But there are certain roads on which I would never attempt it, but all the time you see people do stupid things like your van and trailer man. Now I don't care if people want to kill themselves but I do care if they are endangering me, so give them a wide berth.
That tractor farm thing I was behind on Weds was something else. It filled the left lane and took up a third of the other lane. On one stretch, through a rural village with little traffic islands every few metres, it just drove 3/4 on the pavement to get through the narrowings, and at quite a pace. Thank God there wasn't some little old granny tottering along going about her business, otherwise it would've been, bye-bye grandma!
I did eventually overtake him at Chilham where the road widens, and then he was a speck in the rear view mirror, lol.
As for motorway/A road slip road runs - love them. Every morning I drive down the A2 slip road and gives me a thrill every time.