What is the criteria for aws warnings for speed reductions. Is it more than a 1/3 reduction or am I wrong? And how far out from the reduction is it meant to sound etc? Or is the warning before the warning board. Hope that makes sense??
There should be an AWS ramp before every signal and speed restriction (with exemptions, for example at tight junctions).
Irl when driving we know where the speed limits are you will only get an AWS warning for a speed reduction if it is a big drop in the speed you don’t get them for every speed reduction. for AWS with signals you will have an AWS ramp at every running signal. Apart from big terminus stations where it is to complex to signal the ramps into and would just cause confusion so you don’t get them at every signal per se as above has claimed. You also won’t have them for position light shunts. they are placed 185mtrs before a signal/ speed warning board as a standard distance.
Specifically, an advance warning board and associated AWS magnet is provided if the reduction in speed is greater than 30%. This includes if the reduction is in steps - e.g. if there’s a reduction from 125mph to 100mph then immediately another reduction from 100mph to 80mph, you get the advance warning because the total reduction is more than 30%, even though each of the individual reductions is less than 30%. An advance warning board and AWS magnet can also be provided for other speed reductions which do not meet the above criteria, if the location is considered particularly high risk for some reason.
Normally 183 metres (200 yards) before, although location of infrastructure such as pointwork can mean there's some variation in that.
