Tuesday, May 18, 2010

Flawed case for 20mph urban speed limits

Much has been written recently about the proposal to introduce 20mph urban speed limits.

Numerous articles have popped up in both the mainstream and motoring media to say what a good idea it would be to reduce limits on residential roads from 30mph down to 20mph.

The focus of most of the articles has been statistics showing the number of lives that can purportedly be saved by such a 10mph reduction.

Typical of the genre was Andrew Neather writing not so long ago in the Evening Standard.

He points to accident statistics contained in the mysterious "One study". Who it was conducted by and what their agenda and methodology may be isn't stated.

But who cares, right? Because it somehow offers the claim that "20mph limits reduce road injuries by more than 40 per cent" and it appears that bit is just too juicy not to quote.

Yet when you think about this stat for a moment, it cannot possibly bear any relation to reality.

A car hitting someone at virtually any speed will cause something as vaguely defined as "road injuries". So what this study appears to suggest is that a mere 10mph cut in speed means almost half of pedestrians or cyclists who unfortunately wander into the path of moving vehicles won't be hit at all.

Almost half? As a result of 10mph? That seems extraordinarily unlikely. One big question mark against the accuracy of that particular study, for starters. Or maybe just how Mr Neather has represented its conclusions.

Piled on this failing, I'm willing to bet, is the fault of omission. Did this study also factor in the likelihood of additional accidents due to driver inattention? Being limited to 20mph is so ridiculously low that, while crawling along, people will very likely spend their time looking out of the window or fiddling with their stereo.

The result may just be more accidents.

In any case, following the argument that saving lives must always trump traffic speed, without looking at the bigger picture, will inevitably bring all traffic to a total halt.

Unless, at some point, you come to terms with the fact that things that move will inevitably be involved in accidents; that pedestrians must also carry some responsibilty for avoiding vehicles and it's not always the driver's fault; and that our economy depends fundamentally on people and goods moving around, so they must be allowed to do so at a reasonable speed.

The line of compromise must be drawn somewhere and, beyond their use in certain limited areas, such as outside schools, it seems to me 20mph limits clearly cross it.

Stats distraction

But even flinging potential numbers of lives lost or saved back and forth, accurate or otherwise, misses the point. Due to one crucial detail.

The plan is to police these new limits with a comprehensive (and no doubt extremely expensive) network of mass surveillance cameras recording every vehicle movement within an area and measuring average speed.

And that's why the proposal won't, in fact, cut speeding at all.

First, virtually all residential roads on which a driver might technically be capable of reaching 30mph will already have been road-humped to stop-start oblivion.

It's already impossible to reach even 20mph consistently, particularly in London, without regurgitating your spleen and smashing your car's suspension into tiny pieces.

Second, even if your wallet will stand bouncing and crashing your pride and joy over humps at 20mph, or you even find a rare, hump-free road, the time any driver will spend travelling at the maximum permitted speed relative to negotiating junctions, dodging other cars and sitting at traffic lights will be tiny.

All the times they simply cannot avoid going slower and stopping altogether between one camera and the next is why limits measured by average speed won't remotely curb anyone who gets the opportunity to rocket briefly, but no less dangerously, down residential streets.

Real agenda

So if the plan so blatantly won't work to curb speeding, why is it being proposed at all?

The answer can only be that these new limits are not really about speed, but about justifying the installation of the auto-recording camera network required to police them.

That is the real goal. Mass surveillance.

Such a plan has to go hand-in-hand with reduced limits, because the idea of anyone being able to travel through a network of residential roads at an average of 30mph is just plain laughable.

Can it really be a coincidence that this 20mph proposal has emerged so soon after it has become clear - thanks particularly to the election of Boris Johnson as London mayor and a big 'No' vote in Manchester - that congestion charging, and the similar mass-recording camera network required to police it, will be spreading no further for the foreseeable future?

As if by magic, a new justification for the excessive, automatic monitoring by camera of our every movement is being whipped up.

So what a shame it is that some commentators - even those writing for respected car magazines that really should know better - appear to take such a shallow view of the issue as to have fallen for the spin and lame statistics being put about by those who are, in truth, seeking only to expand our already over-developed surveillance state.