I am one of the 70% of the UK population who supports the use of speed cameras. I would, however, like to take issue with the statistics used in your article 'Camera controversy' (NCE last week).
The 35% reduction in collisions at speed camera sites is misleading. The requirement of four or more fatal or serious accidents within a two year period for camera placement is the reason.
Unless there has been a continual average of this figure over many years, then the occurrence of the four or more serious accidents will be a statistical blip, albeit an extremely sad and distressing blip. Whether a camera is, or is not, placed at the site, there will be a tendency for accident reduction over the following years.
Dr J Ross Hawkins, Cambridge, rhawkins@nibsc. ac. uk