They interfere with road workers, look bad and and shouldnt be allowed.
I'm all for providing education to people about the hazards of driving under the influence of alcohol or drugs; and allowing people to grieve the loss of a loved one due to alcohol or drug related vehicle accidents. However, I'm not too sure that roadside markers of the scene of an accident is the proper way to do all that. Presents a visual distraction for other drivers, and can be a problem for road crews as you posted.