Only 20 years ago, car ownership was, incredibly, half what it is today. Roads were places where people lived, walked, cycled, talked, shopped - and drove.

Today, roads are thoroughfares where motorised traffic is king. Comfort and speed are everything, which would be fine were it not for the problems this causes.

Feeling intimidated by traffic is one of the commonest reasons given for not cycling. Dense traffic, especially if it's speeding, poses a danger and deters thousands from cycling, especially those with children.

Ironically, it's those with children in their cars at school run times who tend to be the least aware and hence the most dangerous drivers.

A 20mph speed limit would be the single most effective measure in making the roads safer and encouraging cycling.

Increased cycling benefits everyone: statistically, the more cyclists there are, the safer it is to cycle. Critical mass in action. More cyclists equals fewer car journeys, freeing up road space for those who still need to drive and for buses. With a 20mph limit, cycle lanes wouldn't be needed. Pavement cycle-paths could be given back to the pedestrians because even novice cyclists wouldn't need them.

Cars circulating a city at 20mph wouldn't require as many signalled junctions, so a lot of traffic lights would go. The civilising effect of lower speeds makes streets pleasanter places. It's easy to hold a conversation in a street in which speeds are under 20mph.

Travelling slowly, you engage with the environment through which you are passing. By walking or cycling in the street, you are a part of it rather than riding roughshod over it. It is astonishing how differently people behave from within the insulation of their car.

At 20mph, drivers make eye contact with and engage with the people in the street. Cyclists and pedestrians know they've been seen. It also makes the driver less inclined to bully his way along "his" road, and more inclined to share the space.

At speeds over 30mph, drivers begin to become dissociated from the area they are passing through. They see less and care less. Cars, especially speeding cars, destroy communities.

In many side roads, cars ignore what would be a safe speed and drive at the 30mph limit as of right. That's why it's high time communities reclaimed their streets - their spaces - by recording the speeds that cars do, and using this evidence to get the limits reduced.

So, when the city council's speed guns become available, borrow one and make good use of it.

It would cost just £300,000 to create a 20mph limit in Oxford. And further good news is that speed reduction needn't mean unpopular humps and ugly Gatso cameras.

Lower speeds are best encouraged by creating environments which look like the sort of place where drivers would not want to drive quickly. Lower speeds are achieved by removing barriers between drivers and other road users.

Lowering speeds means turning streets back into the places they once were, rather than the monuments to motoring convenience that they have become.