Sir – I’m puzzled. As I drive into my little network of roads in North Oxford, I see self-congratulatory signs telling me that ‘It’s 20 for a reason’. I agree: it’s impossible to drive at more than 20, because of the pernicious speed bumps and hollows that have been introduced into our streets — let alone the illegally-parked vans.

And, anyway, it’s been 20 on these streets for all of the four years that I’ve lived in Oxford — so why do I need to be reminded at the public expense?

To me, this, more than the argument about whether cars and drivers perform better at 20 rather than 30mph, is the central issue.

How much of citizens’ money has been wasted on all this nonsense? I have driven down the Botley and Iffley Roads and seen huge signs which have been put up at the entrance to all of the narrow streets which, I know from experience, cannot be navigated at more than 10mph. The cost must be enormous — to absolutely no effect.

Insult is added when the sign ‘It’s 20 for a reason’ is added. As an ex-adman, I can confidently state that this is lamentable copywriting. It neither tells you the reason, nor the reason for the reason. I really hope that this slogan was coined by some junior official in the council, and that they didn’t pay a well-reasoned professional charge of £100,000 to develop this. Please tell me I’m right.

Nigel Clarke Oxford