Going southbound on the A1 yesterday, after doing deliveries in Yorkshire, (i'm a Class 1 HGV driver). I was approaching the junction with the A607 at Grantham, traffic was slowing to exit the carriageway, so I backed off on my speed. When they had gone I increased my speed, then I saw two vehicles on the entry slip, next thing I know i'm hard on the brakes because some idiot had decided to slow to virtual stop to let them on to the carriageway. To avoid that I could have gone into lane two, but that lane was full of traffic.
If I was fully laden to 44 Tonnes, the car would have been fit only for the scrap yard, and the driver would have spent the weekend, or longer in Hospital.