REGARDING the Lancashire Telegraph’s ‘Twenty is Plenty’ campaign, first of all there is no long-term proof that 20mph limits by themselves reduce accidents. Look at last year’s casualties – they rose across the country. However, this is widely regarded as a statistical blip as this year’s have fallen again.

The biggest scheme implemented and studied was in Portsmouth where an extensive 20mph scheme was introduced and it had zero effect on casualties in the longer term. In fact, in some locations, casualties increased.

It is no good slapping on lower speed limits as it is well-proven that drivers will in general adjust their speed according to what the road environment is telling them, not because a sign says so. Bull Hill in Darwen is a prime example of this basic, psychological fact.

The problem for most areas is that casualties are not, for the most part, due to any specific cause that can be solved by a lower speed limit or providing physical measures such as crossings and the like. They are random occurrences.

It is also worth noting that the casualty statistics include any injury accident on the highway – I note there are some statistics in the borough where drunk people have injured themselves falling out of or on to vehicles. These are counted as a road traffic injury accident and will be a black mark on the authority.

But should they be taken into account?

If the Telegraph was really serious about cutting casualties, one of their journalists would be poring through the casualty statistics to see exactly where the problem areas are and what the causal factors are and what could be done to mitigate them, rather than embarking on a politically and emotionally misguided campaign to spend hundreds of thousands of pounds of taxpayers money on installing largely meaningless speed limits.

s_smith (via website)