Why?
There are no "Give Way" or "Stop" signs on the major road, traffic flow is not that heavy, speeds are higher because of the nature of the road, but numpty still decides to stop t allow traffic out despite the fact that 20 seconds after he/she has passed the carriageway would be clear anyway!
They think they are being courteous, but cannot see that they are also leaving themselves open for points and big fine for careless driving and increasing the risk of being involved in a rear end shunt.
Some drivers really are morons🙄