In this village, CRW used both a logger and a SID (Speed Indicating Devivce). 

The logger records time and speed of traffic in both directions, which is why it is labelled as bi-directional in the photograph. The logger, that does not display vehicle speeds, was used to establish a base line of typical speeds through the village. The results from this survey are shown in the first two charts. The first shows the speeds inbound (Log0BOX:ElsworthRd IB LPost). The second chart shows the speeds outbound (Log0BOX:Elsworth Rd Outbound). On both charts the limit—30mph is shown so that the number exceeding that speed can be easily seen. On the outbound chart, those over 50mph in the 30 zone can be seen, 36 vehicles in 3 days.

The SID, that records in one direction only,  was then placed for three weeks on a lamp post to display speeds to outbound drivers. The data from the SID shows that only 14 vehicles exceeded 50mph during that 3 week period.

In addition, calculating the 85th percentile speed in each case, it dropped from 41mph with no speed indication to 34·2mph with the SID Indicating speeds to motorists and the public thus proving that properly placed SIDs do have an effect and can moderate the speed of traffic.