Helen Croydon: Will the real road signs please stand out

There is something about road signs which gives people comedic value to steal them. I lived next door to a boy at university who hung them in his room – grit included – as wall candy. Most sign swipers though don't have the audacity to send them to Bonhams auction house and pass them off as Victorian memorabilia from Downing Street.

It would have been a pretty good stunt had Cambridge Council not stepped in at the last minute suggesting that the sign, planned for sale yesterday, was actually from Downing Street CB2, not Downing Street WC1. Bonhams pulled it from sale, citing "provenance issues".

If the suspicion is proven, this would not be the first piece of stolen topographical property. Cambridge City Council says they recently caught someone selling a plaque for Tennis Court Road on eBay. So now I understand where Britain's road signs go – bedrooms and auction houses.

But such is the curious relationship we have with road signs. Out of context, they take on a surreal quality, and are a source of fascination and amusement. But it's different when we attempt to engage with them in situ, as it were.

At the weekend my car got towed away. It wasn't so much the £260 fee that made me swear loudly, but the fact that I couldn't find the car pound. Regis Road in north-west London, which is where a cab driver had the pleasure of transporting my ranting self to, only has a sign on one side of the street. From the direction we approached it wasn't visible. Naturally we sailed straight past, effecting a diatribe from me about the lack of directional road signs in Great Britain.

The week before, and I didn't care if was listening – I missed the turning for Weybridge on the anti-clockwise M25 because the sign isn't actually visible until you are on the slip road, meaning I ended up somewhere near Gatwick before I knew to turn around. Sometimes signs just stop. Chapel-en-le-Frith, straight on, one will avouch. Then you come to a T-junction and there's nothing.

The Highways Agency, which is responsible for major roads and motorways in England, seems to have abandoned directional signs since Sat Nav, which I stubbornly refuse to purchase, became mainstream. One friend, driving to Cornwall from London, told me he was directed not to St Ives, but to Gnome World. He was told he had reached his destination but there he was – trapped on Dartmoor, surrounded by gnomes.

Urban street signage is no better. Roads are often either unnamed or the sign is obscured. A cul-de-sac near me was changed (with a marker pen) from "Gay Close" to "Gayboy Close" and stayed that way for months. Roads are awarded a sign but then mysteriously change names half way along.

Once you've established the street, there is the building number to find. I cricked my neck walking along High Holborn in central London last week, looking up for number 252. Building numbers are the proprietor's responsibility, not the council's, so anyone without a placard loses business and infuriates guests at their peril. As for those who insist on a house name instead of a number – plain selfish.