Traffic light rating system

A traffic light rating system is a system for indicating the status of a variable using the red, amber, or green of traffic lights.

Food
Food sold prepacked may be labelled with a traffic light label showing how much fat, saturated fats, sugar, and salt are in that food by using the traffic light signals for high (red), medium (amber) and low (green) percentages for each of these ingredients. Foods with 'green' indicators are healthier and to be preferred over those with 'red' ones. The label is on the front of the package and easier to spot and interpret than Guideline Daily Amount (GDA) labelling which will continue. The GDA is difficult to understand for many, including children, and does not lend itself to quick comparisons. The use of traffic light labelling is supported by many physician groups including the British Medical Association and welcomed by consumers. Despite worries from some in the food industry that red foods would be shunned, the British Medical Association, Food Standards Agency and others agree that consumers interpret the labels sensibly, realise they can have red foods as a 'treat', and they are easier to understand than lists of percentages.

Currently the traffic light label is used in some European countries on a voluntary basis.

Other labelling
White goods must be labelled with a label indicating energy consumption. This is not strictly a 'traffic light' but by analogy a scale of seven values that run from red to green through intermediate colours.

The system may also be used for the European Game Information System (PEGI), which puts age ratings onto video games. Again this is not strictly a 'traffic light' since there are likely to be more than three colours.

Performance monitoring
In many factories, different stations on the production line(s) are equipped with factory monitoring and control systems; attached to such systems is a 'traffic light' status indicator which is generally visible from many places within the factory. Green typically indicates normal levels of production; amber indicates that production has slowed (or attention is otherwise warranted); red indicates that production has stopped or the line is down.

In the British Civil Service and other departments of the United Kingdom government, traffic lights are used as a coding system for good or bad performance - usually known as a 'RAG rating'. For example in relation to the workload performance, red would mean inadequate, amber would mean reasonable, and green would mean ideal. The letters R, A and G are used in addition to swatches of colour, so that the system can be used by colour blind readers.

Traffic Light RAG and BRAG (or RAGB) Milestone Project, Program and Portfolio status reporting
When status reporting how well a milestone, project, program or portfolio is performing or being delivered, project managers often use a RAG rating to indicate how on track or at risk is the project, its deliverables or tasks.

More recently an additional status colour of Blue has been included to show where milestones or components of a milestone, project, program or portfolio are complete. This BRAG (or RAGB) status was initially introduced by Tom Daniel (formerly of the Blues and Royals) at Dell Computers Inc in 2000, and thereafter at Deloitte Consulting UK (corporate colours for his employers were or are all blue ) where he introduced a variation of a blue milestone with a red outline for delivered or completed but late. This ensured late delivery remained visible as opposed to focus simply switching to other areas of a program where the status might turn red (through an inter-dependency) as a result of the late delivery and no fault of that area. In 2009 he introduced Magenta milestones to show where they were new or changed. These variations have started to be used in clients he has worked in such as British Telecom.

Behavioural
Some organisations, such as the U.S. Navy, use traffic light terminology for sexual harassment education. Green light behaviour is normal discussions or actions, such as discussing work or assisting someone on stairs. Amber light behaviour is potentially offensive behavior, such as sexist jokes or patting someone on the behind. Red light behaviour is obvious sexual harassment such as sexual requests.