Sir – The context of the debate about the 20mph speed limits is that more than 5,000 pedestrians are killed or seriously injured in Britain each year while the speed limit in residential areas is routinely exceeded on some roads.

The use of 20mph limits has been found to be effective — for example in a 2010 Department for Transport report on a scheme in Portsmouth — and a majority of drivers are in favour of them.

Clearly, the level of compliance of a scheme is determined by public acceptance, and this, in turn, is influenced by the presentation of the schemes in the media.

A few decades ago when drink-driving laws were tightened, there was vocal opposition motivated by commercial concerns, worries about individual liberty and self-interest. Looking back, it is hard to understand how some in the community expected their “one for the road” to be paid for in the misery of victims and their families.

Bearing in mind the evidence, it is also equally hard to understand the opposition of some to the 20mph limits expressed in recent weeks.

Paul Moore, Oxford