COMMENT: Let's delegate the decision to local areas

Slowing traffic down will make many streets safer and less off-putting and intimidating for pedestrians and cyclists, encouraging a healthier lifestyle.

More 20mph zones would be a good thing. Few people would disagree with that. Safer streets outside our schools, shops and homes. What’s not to like about that?

He is probably right as well to say that making them more widespread will encourage people to take them more seriously, although there must be some caveats to that.

What happens when 20mph zones are introduced indiscriminately on roads where drivers’ instincts tell them it is safe to go at 30mph? There are several busy arterial roads around the city where motorists might make that judgement. What happens then? Many will doubtless drive at the speed they always have and pass through the neighbourhood safely as they always have.

With no enforcement of the lower limit, the old 30mph would then continue by default. There would be no benefit from the slower traffic, but a real risk of tailgating from some impatient drivers when some vehicles slow down to 20mph.

Legislating against something that goes against instincts which people have learned over many years, without any enforcement, is always going to be difficult.

This newspaper is inclined to agree with the Transport Minister.

A central edict on the subject is too blunt an instrument and local authorities should be encouraged to consider more 20mph zones and “do what’s appropriate for them in built-up and residential areas”. That means taking a judgement on particular streets in particular areas.

What has proved controversial about the plans adopted in the Capital is the near blanket imposition of the lower limit across the vast majority of the city’s streets. Perhaps the city should consider adopting Mr Mackay’s approach and delegating decisions to neighbourhoods who can decide for themselves which streets would benefit from 20mph and which are safe at 30mph?