To be honest, around 90% of drivers a fecking morons. Motorway driving is especially bad. Most folk don't understand that the right hand lane(s) is for overtaking, not for sitting in and going 3mph faster than a lorry that's still 300 yards up the road.
I'd say I undertake an average of 10 people a day, solely through using the motorway properly, while they use it improperly.