Traffic Light principles explained
The graphs below demonstrate the methodology behind each type of traffic light. The graphs are illustrative and do not represent any actual indicators.
 Green 1 and 2: An indicator where rural areas perform above or equal to the norm, with a trajectory suggesting that it will remain so.Green 3: An indicator that is below, but within an acceptable range of the norm with a trajectory that remains within an acceptable range.
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 Amber/Green: An indicator where rural areas perform below an acceptable range of the norm, but with a converging trajectory that will converge within an acceptable time frame. |
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 Amber/Red 1: Rural areas performing equally to the norm, but trajectory will clearly take rural below the norm. Amber/Red 2: Indicator where rural performs below the norm with a converging trajectory that will converge outside an acceptable time-frame. |
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Red 1 and 2: An indicator where rural areas perform below an acceptable range of the norm with either a parallel or diverging trajectory. |
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The norm represents the England average and is, for the purpose of illustrating the principles, set at 100.
13 June 2008