In all fairness Iran drivers are good as gold when compared to the driving standard in Pakistan.
Trucks are carrying no less than 200-250 tonnes (not joking) and they dont have enough power to even move, most people drive with the full beam on, most motorcycles dont have working lights, buses and coaches dont have working lights, there is no right of way anywhere just each to their own, protect yourself is the theme here, it is normal practice to go wrong way on any road including motorways.
I have driven 1300 miles in Karachi since being here and have averaged 15 MPG because the traffic is unreal, you get up to 40mph and a motorbike or a rickshaw will swerve in front of you. Karachi traffic is enjoyable at times in a small car but not in the 430.