Always Drive at a Safe Speed
This is a dashcam video taken during a normal drive. What happens is a car towing a trailer crosses the solid white line in order to reverse into a field for loading.
The site is a well known accident blackspot on a fast moving road where fatalities have occurred. This could have been a disaster in the wrong situation, but shows the importance of driving at a speed which will allow you to stop well within the distance you can see to be clear.