Ted Dewan first grabbed my attention with the Cyclemas tree in Gloucester Green, December 2004. This 20ft alternative Christmas tree was made from 40 abandoned bikes and decorated with lights. Now, the children's author and illustrator is back as head witch of Roadwitch, Street safety with a smile (Oxford Mail, June 24). Roadwitch combines public art, traffic calming, safety campaigning and community building. See www.roadwitch.org.uk for details.

Roadwitch is based in Beech Croft Road, Summertown, Oxford, where annual street parties have closed the road to motor vehicles and redesignated the street as a living room. Residents with TVs and sofas can enjoy some car-free peace and quiet for the day. The new Lord Mayor, Jim Campbell, opened this year's party with a bicycle loop for the local children. The children then produced a home-made speed camera built for the launch of Oxford's road-reclamation initiative - Life Begins At 20 (LB@20).

LB@20 is a new campaign for a 20mph speed limit on Oxford's streets. The popular reclamation of Beech Croft Road is precisely the effect that LB@20 would like to see replicated around the city. As Mr Dewan explains: "Life on the street could really begin take root if a genuine 20mph limit were adhered to, and if the layout of the street expressed its role as a living space rather than a traffic conduit."

Thames Valley Police, acting on a few outsiders' complaints, have already asked Mr Dewan to remove the bogus speed camera. Legally, 'rubbish' must be removed. "It isn't rubbish," points out Mr Dewan. "It's art. It's creative mischief without anger - and it's on my own property."

LB@20 is helping Oxford community groups to return local streets to residents. The group is building up to a public meeting preceding this year's national '20's Plenty Action Day' in November. Campaign coordinator Paul Cullen says: "Across the city, people of all ages find themselves unable to use their streets as they would like. This is especially true for children. A big factor whether it's a residential street or a shopping street - is the speed at which people pass through in motor vehicles." The idea isn't as crazy as it sounds. It is a traffic-engineering fact that vehicles travelling at 20mph get through a city more quickly than those racing from one queue to the next at 30-40mph.

Oxford's cycling Lord Mayor, and almost all its councillors, sensibly agree that a 20mph limit will transform the experience of living in the city. Emergency services will enjoy the reduction in traffic accidents. Health officials love the idea because we'll all become healthier. Kids and parents love the idea because they can play in the street and cycle to school more safely.

It's a pity that so many drivers, many of them professionals, have such a cavalier attitude to obeying speed limits, especially in areas of known danger. The sooner a blanket 20mph system is introduced and enforced, the better. Everyone in Oxford is a winner at 20mph. Is there anyone out there daft enough NOT to agree that Life Begins at 20?