there are lots of reasons to welcome the rolling out of 20mph zones across the Capital.
Slowing down traffic will make most of our streets safer and the areas around them more pleasant places to live, shop or otherwise spend time.
The evidence from cities in England suggests serious road accidents involving children could be cut by as much as two-thirds by such a scheme. That, of course, has to be a good thing.
More 20mph zones should also make us a healthier city, by encouraging even more of us to get out on our bikes.
Yet concerns remain about whether the scheme which the city has planned can deliver the potential benefits and avoid the pitfalls.
The most serious concerns revolve around enforcement and the one-size-fits-almost-all approach.
We know that the police are committed to enforcing the new limit – within existing resources – but what that will mean in reality remains unclear.
It is most likely that enforcement will be indiscriminate as it currently is on most other roads. The risk is that most motorists will get used to flouting the new limit and end up following the pace of other traffic on the road. Spot checks would then be carried out by police in which a small number of drivers would end up getting fined for driving at 30mph on roads which are presently 30mph limits. That would be neither effective nor fair.
It’s far better to identify the roads where speeding is a problem and use the resources available to effectively enforce a safe limit on them.
That leads on to the other major issue – the blanket approach that is being taken to all but the busiest arterial routes. Some roads are still safe to drive on at 30mph. Making them 20mph will only make getting about the Capital a frustratingly slow business. Lothian Buses has warned that could lead to higher bus fares and a poorer service.
If councillors are minded to press ahead with this bold experiment in anything like its current form, there is one thing they have to do.
Just as the changes to traffic arrangements in the city centre were sensibly introduced on a trial basis, so too there must be a sunset clause in the 20mph plans. It should force the next administration to carry out a meaningful review to identify which streets are safer and which are just slower and higher limits brought back anywhere it makes sense.