The Evening Express reports that 11 Aberdeen drivers were caught breaking a 20MPH limit since 2009. Maybe Aberdeen drivers are much more careful and considerate than average, but somehow I doubt it. Speeding in Aberdeen is likely no more or less of a problem than anywhere else in the UK, and those 11 drivers will represent an almost infinitessimally small fraction of the total offences. I live on a 20MPH road, and because there's ineffective physical traffic calming, the only person actually driving at 20MPH on it is me, on the rare occasions that I drive. On one occasion, my aberrant behaviour prompted an annoyed honking from an impatient driver behind, who couldn't comprehend the idea that someone might actually respect the speed limit.
Sadly, the police take the same relaxed view of 20MPH limits as the average driver, which is why they don't bother enforcing it. They have better things to do, like ticketing cyclists on Chelsea Bridge.
But driving at 25 or 30 isn't such a big deal, right? Not exactly. Research shows that children cannot judge the approach of cars at more than 20MPH, making collisions more likely. For families, having to worry about speeding cars makes the difference between being able to cross the road in a relaxed manner and having to wait at the kerb for an extended time and then scurry across dragging your kids with you. At 30MPH, cars dominate the road and as a pedestrian you'd better watch out. 20MPH, properly enforced, makes a street a markedly less hostile place for pedestrians and cyclists. In terms of safety, both the number and severity of collisions increase markedly with higher speeds. Noise levels in residential areas are increased with higher traffic speeds. In short, with average speeds approaching 30MPH, streets become less pleasant, more car-centric, more dangerous places.
As the Parliamentary Advisory Council for Transport Safety (PACTS) notes,
"In order for the vision [of reducing risk on the roads] to be adopted and for a programme of action to be implemented to achieve it, a high level of political leadership is required. Part of the difficulty in generating political leadership is the conflict between the public’s expressed concern about safety on the roads and their ambivalence about some of the actions necessary to reduce casualties, particularly on the issue of speed management. To continue to achieve casualty reductions in the UK in future years, focused, co-operative and co-ordinated campaigns by a range of non-government organisations will be needed to build public support for the implementation of necessary interventions."
In other words, marrying speed cameras with 'the war on the motorist' in the public's mind is hardly likely to get people to slow down in residential areas. If Philip Hammond's doesn't take speeding seriously, it's not reasonable to think that drivers in Aberdeen will either.