Sir – Your 20mph speed survey (Report, March 4) came to an odd conclusion. Despite finding that more drivers are obeying the law, it starts, “Driving experts questioned the need for Oxford’s 20mph limits after it emerged motorists are still ignoring the restrictions.”

Must drivers only comply with laws they believe are fair, then? No one would apply this weird logic to any other law. If a law is flouted, surely lack of enforcement is the problem, not the measure itself.

The speed survey on Morrell Avenue found a ten per cent improvement in motorists obeying the law since September 2009. Only 38 per cent were going over 25mph. That’s a great improvement on a road where speeds were often over 40mph. Nationally, speeds on 30mph roads average just over 30, and on 20mph roads just over 20. This is, I suspect, what planners want for Oxford.

It is ironic that Morrell Avenue isn’t technically 20mph. The 20mph zone “entry” sign at the bottom of the hill has never been installed, so perhaps no one broke the law after all!

Accidents aside, there are many reasons why 20mph matters. Communities across the city asked for streets that are quieter, pleasanter places to live.

Novice cyclists are encouraged to venture out in slower, less threatening traffic.

Everybody can cross roads more easily. People can sleep better. The limits weren’t introduced to benefit drivers, so it can be hard for drivers to see the point. Yet lower speeds make life better for everyone at little cost to drivers.

While 20mph might feel “too slow”, driving at 30mph makes scant difference to cross-city journeys. You are simply zooming to the next queue.

Better road designs that support 20pmh are incredibly expensive. Until we can afford them, why can’t our police enforce the law?

James Styring, Chairman, Cyclox, the cycling campaign for Oxford