The Revolving Lights units and sirens provide us with a very effective advance warning and we need that so we can take appropriate actions. The quicker we respond to a vehicle needing to pass the quicker they can get on with the business of dealing with emergencies. The range of light bar units is huge and there are some very specific ones and some very generic ones. The light bars chosen by different services will reflect the job they do and the lights will be used to assist them in their job. Traffic advisors built into light bars would typically be used by police vehicles for instance.
