ABSTRACT
The key component of a highway emergency response system is alarm indicator column. It enables either unidirectional or bidirectional communication between the person calling for help and the control centre. Unidirectional communication entails sending a request (by pressing the call help button on alarm indicator column) for help to the control centre. Bidirectional communication is possible when (also by pressing the same call help button on the column) request for help is sent to the control centre followed by voice conversation between the centre and stranded person. By pressing the call help button, the user is automatically sending identification data of the alarm indicator column it used to the control centre. Hence exact location of the accident scene or emergency and consequently the person calling for help is immediately known. Rational measures can be therefore undertaken by road rescue and/or technical services.
