The warning of stationary or approaching emergency vehicles is a safety relevant cooperative ITS service with the main objective to increase the attention of road users for a fast formation of the rescue lane and to inform about a stationary emergency vehicle which safeguards a danger zone or accident.

Emergency vehicles are faced with the following critical and dangerous situations while getting to the emergency scene time:

• Drivers do not react immediately / do not make space.
• In front of red traffic lights, many drivers wait for "green" instead of carefully crossing the stop line and making room for it.
• Hectic – incorrect reactions endanger other traffic or the emergency operation.
• The rescue lane is formed in the wrong place.
• On motorways, the emergency lane is not formed as soon as there is a traffic jam, but only when the emergency vehicles arrive.