How does SID work?

The SID unit flashes the speed of an approaching vehicle when the speed limit is exceeded. The SID unit will record speed and vehicle flow data, however, the SID unit does not record vehicle registration details.

Evaluation

The effectiveness of the SID programme is evaluated regularly and at present, the average speed reduction when deployed is between 3 and 4 mph.

How do I request SID in my area?

The speed indicator programme is currently suspended to new requests until further notice. However, parish/town and borough councils wanting to purchase their own SID can in partnership with Dorset County Council, please refer to guidance notes on this page.

• Speed indicator devices (SID) - questions and answers

• Name: Road Safety Education, Training and Publicity (ETP)
  Email: roadsafety@dorsetcc.gov.uk
  Tel: 01305 224558
  Full details for Road Safety Education, Training and Publicity (ETP)