Safe Speed Forums

Traffic humps and chicanes are used instead but are unpopular, expensive, cause problems for emergency vehicles and add to emissions.

They will need to decide whether the proposed type of speed limit is appropriate to the area, and beneficial in road safety and environmental terms.

20 mph speed limits by signs alone would be most appropriate where 85th percentile speeds are already low and further traffic calming measures are not needed

In France it is my experience that it is rare to be forced to drive through a built up area, there is almost always a bypass/bridge. In this country we are forced to drive/choke on the A6 through Stockport due to some 20 year old mantra that more roads = more cars.
There are some straw for brains about.

No-humping 20mph limit for London

Immediately following this week's demands by safety lobbyists fearing for their jobs that the UK adopt a default 20mph speed limit in urban areas, London Mayor Ken Livingstone popped up aboard the bandwagon (this happened so quickly, indeed, that one might suspect he was aboard in advance).

Mayor Ken - the cheeky chappie's cheeky chappie - announced yesterday that the capital will soon have ANPR* camera-enforced 20mph limits on "every residential street".

Trials are to begin next year, apparently using wireless cameras for ease and economy of installation. Ken's people say the plan is to minimise pain and grief for drivers by eschewing the use of road humps, chicanes etc, which are "cheap and miserable", according to the Mayor.

If technology trials are successful, Mr Livingstone says: "You could roll out camera enforcement of 20mph lanes right the way across London... My broad view is that in a residential area, there should be a 20mph limit... without the road humps there won't be any opposition."

Mayoral road-safety henchperson Jenny Jones told the Evening Standard that "making 20mph the normal speed limit in London would save lives, save money, and give a major boost to cycling[**]. There would be exemptions for some major roads, but all London's residential areas would be covered by the zone.

"The big advantage of having a London wide reduction in the speed limit is that we could reduce speeds without having to put in all the road humps, chicanes, and other traffic calming measures that drivers hate."

It seems that Transport for London (TfL) has £10m to spend on speed limit zones this year; though of course some soreheads may speculate that this will soon be recovered by automated tribute exacted from speeding motorists as they gaily bowl along the hump-free, camera-studded streets of old London town.

There will also be grumbles about surveillance and vehicle tracking. However, Londoners already live and drive within an ANPR panopticon. TfL's congestion-charge cameras are already used by terror plodsto track any vehicle they like and the so-called "Ring of Steel" security cams installed around the City in the wake of various IRA bombings can do it too. This latest extension of plod/spook watching capability will probably pass largely unchallenged.

There's hope for the rebellious tech-head, however, in the news that the cams will be wireless. If they don't have any onboard logging/buffering, one will be able to carry a jammer in one's vehicle and speed with impunity (or, more justifiably perhaps, drive about safely without being tracked).

If the machinery can cope with temporary interference, different measures may be required; but there will be ways to beat the camera, despite the Daily Mail's gloomy prognostications. ®

*Automatic Numberplate Recognition

**Somehow. Your correspondent commutes by cycle, but still can't understand why a 20mph limit for drivers does cyclists a favour.

"The figures destroy the general argument that driving slower means smaller
crashes. Obviously the national picture is telling us something completely
different. In 20mph zones we're having worse crashes than in 30mph zones."

If this is a real affect rather than a statistical anomoly, or misrepresetation of the figures, couldn't it be explained by more people in 20mph zones surviving being struck by a car, where in 30mph zones they are more likey to appear in the death statistics?

In short, increased injury rate in a zone that has a 20mph speed limit is a good thing becuase it means more people are surviving strikes and less people are being killed (as demonstrated by the figures).

Nope. None of the above.

Examine the figures and the claims for yourself.

Hmm, but in your figures you've not taken into account deaths at all.

I don't see how you could discount my theory on that basis.

What Paul seems to have found here is that the Department of Transport are using flawed statistics to force through their policies.

I have just written to my MP on this. I know it's a pain but if enough of us contact the MP's often enough we may get somewhere.

That would be the same flawed statistics that they regurgitated in response to the "scrap speed cameras" e-petition. They even admitted that the statistics were flawed (in that they ignored regression to the mean).

The standard government policy is that if something doesn't work, that's because there isn't enough of it. Good luck with your letter.

The trouble is, and many will back me up on this, there is no evidence that the DfT even care what is sensible [or sane]

Every study of newly introduced 20mph zones shows a decrease in injuries, and an almost total absense of deaths.

That people would use an obviously spurious result to call for the immediate cessation of 20mph zone rollout in residential areas, when all other research show they cut injury and death, says a lot.

Things is, there an obvious spurious result here that will have a logical explanation.

It should be noted that only 15 crashes were fatal in 2006 in 20mph zones, so the numbers may be too small for true statistical significance.

Nevertheless the pattern is preserved. 20mph zone crashes are bigger by this measure too.

Christopher Johnson-Newell was travelling at more than 20mph when he ploughed into the rear doors of the white Volkswagen LT35 van.

Southampton Coroner's Court heard that Mr Johnson-Newell, a keen cyclist, had probably been riding with his head down when the accident took place.
~~~
"The cause of this accident is most likely to be due to inattention of the rider and his riding position," he said.