The other very important reasons for closing the road on both sides include the following:
Emergency responders may have to use and stop on the opposite carriageway to reach the incident
If a fatality has occurred it is inappropriate to allow the public to gawp at the scene and potentially post images on social media before next of kin have been informed
There is a significant chance of additional collisions on the other side due to people gawping at the incident rather than paying attention to their driving
I attended an incident on that very stretch of dual carriageway some years ago and , before the road could be closed , there was an additional multi vehicle pile up on the other side due to rubbernecking ; and despite me placing my van in the fend off position with blue lights operating , so that it could be seen before the bend , around which there was a car on its roof with casualty trapped inside , there were idiots dodging around my van , back into the outside lane , then finding ambulance , fire and police vehicles just beyond and out of sight ; not to mention the artic driver who almost jack knifed by braking at the last moment , despite my purposefully positioning my van where it could be seen from a mile back rather than the hundred or so yards visibility from around the bend to the crash .
Often the public need protection from themselves.
Emergency responders may have to use and stop on the opposite carriageway to reach the incident
If a fatality has occurred it is inappropriate to allow the public to gawp at the scene and potentially post images on social media before next of kin have been informed
There is a significant chance of additional collisions on the other side due to people gawping at the incident rather than paying attention to their driving
I attended an incident on that very stretch of dual carriageway some years ago and , before the road could be closed , there was an additional multi vehicle pile up on the other side due to rubbernecking ; and despite me placing my van in the fend off position with blue lights operating , so that it could be seen before the bend , around which there was a car on its roof with casualty trapped inside , there were idiots dodging around my van , back into the outside lane , then finding ambulance , fire and police vehicles just beyond and out of sight ; not to mention the artic driver who almost jack knifed by braking at the last moment , despite my purposefully positioning my van where it could be seen from a mile back rather than the hundred or so yards visibility from around the bend to the crash .
Often the public need protection from themselves.