Of course you can get bad driving on any kind of road...
If you examine the stats for all road traffic accidents, you'll find that there are far fewer accidents on motorways compared to any other kind of road.
It only takes a momentary lapse in concentration for someone to pull out to overtake, thinking they are on a dual section, when in fact they are on a single carriegeway section, which can of course be quite catastrophic... it has happened several times over the years...
Blame bad driving by all means... but that type of accident cannot arise on a dual carriegeway...
I rest my case, M'Lud.....