WHILE the SNP’s independence bandwagon gets up to ramming speed, the party has been an enthusiastic partner in a move in the opposite direction. First Minister Nicola Sturgeon may have performed a quick U-turn in her speech in central Edinburgh on Tuesday night to tone down her lengthening Westminster charge-sheet, but the administration in which her party is a partner gives no sign of reversing after the first day of the newly expanded 20mph speed limit, which will eventually cover 80 per cent of Edinburgh’s roads at a cost of £2.2 million to the taxpayer.

While the SNP has been happy for the architect of the scheme, the much-derided Labour transport convener Lesley Hinds, to take the inevitable flak, the SNP vice-convener Adam McVey has been enjoying the ride too, saying that the policy “makes streets more attractive to residents, pedestrians, cyclists and children, improves the environment for business and enhances quality of life”.

There is little doubt most people support slower speeds in quiet residential streets and outside schools, but there is scepticism about the effectiveness of the blanket approach Edinburgh is following. And with good reason, because studies of similar projects elsewhere show the impact is marginal. The measure was introduced three years ago in Islington, home of Jeremy Corbyn, and a subsequent assessment by the council did indeed find that average traffic speed had dropped. Prior to the new limit it was 28mph and the 20mph restriction brought it down to 27mph. The same effect was felt in Bristol and Brighton.

Then there is the pollution argument, but again the evidence is mixed. Imperial College London conducted an extensive study in Islington and did indeed find that diesel engines produce less pollution at 20mph, but diesel car sales are dropping because of adverse publicity. However, it also found that petrol cars actually produce higher levels of two key pollutants, nitrogen oxides and carbon dioxide at lower speeds. Awkward.

So at a time when the capital’s council tax bills are increasing by up to £611 a year, the local administration is spending more than £2m on something which evidence suggests will cut speed by just 1mph and the environmental effects are unclear. Included in the cost is a huge number of signs being erected on lamp-posts on streets with traffic calming where it was impossible to drive faster than 20mph anyway, and even narrow cul-de-sacs are getting the treatment.

Publicity now being rolled out across the city states that “Driving at 20mph saves lives” which may well be technically true, but as I’ve written here before the most up-to-date statistics show very few lives are being lost on Edinburgh’s roads, with only two pedestrians killed in 2015. Every death is a tragedy but it is unclear if the new speed limit would have made any difference, and with the average number of pedestrian deaths over the past 11 years below five, accounting for about half of all road fatalities, reducing the number from an already low base will not be easy. Initial reaction yesterday was predictably mixed, with anti-car campaigners claiming to be seeing a marked increase in the number of cyclists on the roads, which is possible but hard to believe. Some drivers reported longer commutes and angry reactions to people adhering to the new rules, with overtaking reported on what were previously 30mph streets.

Half the city is now covered and Police Scotland has been cajoled into conducting spot-checks to catch drivers doing something as heinous as driving at 26mph. And when the force is warning that its manpower will have to be reduced in future, I doubt very much whether the average Edinburgh citizen believes this is the best use of their time.