Is twenty plenty?

October 25th, 2007

There’s been a lot of talk recently about the speed limit on residential roads. First, the Parliamentary Advisory Council for Transport Safety (PACTS) came out last week and said they were in favour of dropping the speed limit from 30mph to 20mph, and that this would halve the number of road deaths.

Then London Mayor Ken Livingstone reiterated that he would like to see 20mph limit introduced in every residential street in London - and said that trials would begin next year using wireless cameras - a move that will mean less time and money spent on road humps. Money aside, there are other potential benefits too, since roads should be safer for pedestrians and cyclists.

So far so good, unless you are the Association of British Drivers (ABD) who claim that 20mph will see more accidents.

The reason? Well, according to Nigel Humphries, ABD spokesperson: “Concentration, alertness, and observation are fundamental factors required for safe driving, which are maximised by the driver setting a speed appropriate for the prevailing road conditions. Forcing drivers to travel below an appropriate speed is therefore detrimental to road safety.” Apparently, the concern is that drivers will spend so much more time reading their speedometer to ensure that they are not breaking the 20mph limit that they will be more likely to not be looking at the road ahead.

Opposing these views, some might argue that drivers get a feel for the speed they are travelling at and will quickly know what 20mph feels like or that it only takes a fraction of a second to glance at one’s speed. Others might argue that the ticketing process can allow for a 2-3mph margin of error, and that in any case statistics show that at 20mph, the results of being hit by a car are far less likely to be serious as at 30mph (serious injury likely) or 40mph (death likely). Yet then, ABD come back with more concerns namely that “a 20 mph speed limit will cause more congestion and increase vehicle emissions” and that (anti-speed cam lobbyists) “Safe Speed has already pointed out that DfT figures for 2006 show that there were more killed or seriously injured casualties in 20 mph zones than in 30 mph zones.”

They say that in war, the first casualty is the truth - and as the residential speed limit debate rages it will be interesting to see what issues are drawn into the battleground. Saving lives and money sounds good, but will this be at the expense of the environment? Doubtless we are likely to see all manner of statistics bandied about in the coming months. Before it gets too out of hand though, it might be worth noting that average car speeds in the UK have just been are reported to be amongst the slowest in Europe (London at 11.8mph is the slowest with Manchester, Edinburgh, Glasgow, Bristol and Belfast all averaging under 20mph).

In this scenario, you have to wonder whether an official reduction from 30 to 20mph would actually make much difference!

Entry Filed under: speeding, traffic, cars