Passive warning
The passive visual warnings are usually just linked to the design of the emergency vehicle equipment and will typically involve the use of high contrast patterns. The older vehicles and those that are in developing countries are likely to have their own pattern painted on them whereas the modern vehicles usually carry the retro-reflective designs. These sophisticated designs reflect light from the torches or the car headlights. The popular patterns include the checker board, stripes or chevrons. In some countries, there are additions to the retro-reflective markings. The vehicles are now being painted with bright yellow or with orange color underneath them in order to maximize the visual impact of the vehicle. Another passive marking is in the form of emergency service spelled out in reverse which is placed in front of the vehicle like the fire or ambulance truck. This will enable the drivers of other vehicles to identify easily the approaching emergency vehicle by looking at their rear view mirrors. The vehicle can also display the name of the operator or owner of the vehicle and a telephone number which is used in calling the vehicle.
Ambulances also carry with them an emblem which is either part of the passive warning category of not. Some ambulances also display a Red Crescent, Red Cross or a Red Diamond which is collectively known as the Protective Symbols. The symbols were being laid down by the Geneva Conventions. All countries present during the convention signed to agree to restrict the use of their National Red Cross or military ambulance. If the vehicles are used by other organizations, agencies or people there will be a breach in the international law. The protective symbols are being designed in order to indicate to everyone especially during war that the vehicle is neutral and that it should not be fired upon. This will give protection to the medics as well as their casualties although this law has not always been heeded. In many war stricken countries, there ae breach of these laws happening on a daily basis.