Our roads here in Norfolk are lovely (to me). Most are only single carriageways, and with the exception of Norwich, have very little traffic on them. We don't have even a smidgeon of a motorway. The main A road which bypasses our village for example is nearly always empty, and one never has to wait to join it. But as with all rural roads, one has to expect the unexpected. There are loads of farm vehicles of all types trundling along, but the tractor men are very good and pull over regularly into lay-bys to let the other motorists pass. One can encounter horses, and lots of pedal bikes. At night, the deer, foxes, badgers and hares throng the place, you can hardly move for them. As in anything else, one only needs a bit of my old mate Common Sense.
My old dad used to say that one drives according to one's personality., and aggression, impatience etc will out. This woman obviously had 'issues' which made her a dangerous and bad driver.
Thank you everyone for your advice and comments. Another time (hope not!) I'll be even more defensive and turn off safely out of the way. People like that are better miles in front of one than right up one's bum!