SIDS – SPEED INDICATOR DEVICE
SIDs accurately measure the oncoming vehicles speed and displays this value to the driver. A number of variations are available, including portable versions that can be carried and installed on different sites by a single person. The sign face itself can also display a number of different messages along with the speed.
SIDs are cost effective compared with road humps, chicanes and other expensive measures, they pose no problem for emergency vehicles, whilst noise and nuisance are totally absent.
Transport for London Street Management’s Report on the Effectiveness of SIDS Reducing Vehicle Speeds concluded that SIDs are effective at reducing speeds, reducing speeds 200 metres downstream of the sign and a collision reduction of 5.6%.
This report also found that an efficient method of operating SIDs was to rotate them around several sites. Westcotec’s portable SID is shown to be ideal.