Road Safety Speed Indicator Display

SID stands for Speed Indicator Display. SID is a mobile vehicular actuated sign, which reminds and raises motorist’s awareness of their speed and encourages them to drive within the speed limit.

SID is an interactive variable message sign that is portable, capable of measuring and recording vehicle speeds. It displays the motorist’s speed, with a view to encouraging them to drive within the speed limit. SID is essentially the friendly side of speed enforcement, non-threatening but never the less effective. Speeds have shown to be reduced during SID’s visits and early monitoring of accidents, shows pleasing result.

SID works by embarrassing motorists into complying with speed limits, by displaying their speed for all to see. If drivers are within the limit their speed is displayed followed by a smiling face, as if to say thank you. If the speed displayed is above the speed limit, then SID produces a disapproving frown.

SID is deployed anywhere in the county where there may be a perceived speeding problem within a 20, 30 or 40mph speed limit. SID will be deployed at requested location (as long as it is safe to do so) for a hour at a time. Each requested location will receive 3 visits and speeds will be recorded and downloaded.

Once 3 visits have been undertaken, each site is ranked against all others visited throughout Suffolk, to determine their re-visit criteria.  The data collected by SID is available by clicking on the link here.  If the data recorded at a location is found to be above the Police’s enforcement level, this information is passed to the police.

The deployment of SID is via SID cars, these are specially liveried Smart Cars resplendent in yellow and black paint work. The object is high visibility but friendly persuasion speed compliance.

To request a SID please contact our Customer Service Centre.

If you require information about the enforcement of existing speed limits please contact Suffolk Police.