New speed limit on the A406 Gunnersbury

[DavidNW9]

Too late for me, they've just (ie this week) changed the southern part of Gunnersbury Avenue to 30, kept the cameras and now place the 40 signs just beyond them. It's the first time in my life I've been caught as I use this road every week and it's been 40 for decades. But anyone else using it it's not 40 any more so have to wait till past the camera. Clearly nothing to do with safety, Hounslow presumably needed a bit more cash for this year's budget. Here's an article proving they make absolutely no difference. http://www.thenewspaper.com/news/16/1686.asp

On a side note what percentage are actually on overall so I know the chance of being missed, 80% or so I'd have guessed? This says 44% in 2011 but mainly on or off the whole time. If anyone has the local figures please let me know. http://www.dailymail.co.uk/news/article ... nders.html
In 2011 but out of date now. "London’s Metropolitan Police has more camera sites than any other at 468 but only 56 per cent are in operation at any one time"

It appears to have been implemented because of the bridgeworks which stop hundreds of yards before the 40 signs. Will they revert to the old border when they finish in two years? Unlikely.

https://www.thegazette.co.uk/notice/2118119

[Andy33gmail]

Hard to comment without seeing it, but certainly I'm always losing track of the speed limits on London's trunk roads, and it's seems bizarre that roads safe for 50-80mph are restricted to between 20-40mph. Conflating pollution, safety and local politics when setting limits doesn't help anyone anyway.

Interesting point about speeding being represented more overall than in crashes - all being the same, that would suggest that driving faster is safer, presumably because the safer roads encourage both higher speeds and fewer crashes?

I don't have time to find the cite now (and I apologise for the lack of precision in the statement), but it reminds me of some statistics I found a while back showing that most people breathalysed other the limit after a crash were young while most people caught randomly were old. Suggesting either that old people are less affected or just that young people are so much more likely to crash in the first place.

[michael769]

I don't have time to find the cite now (and I apologise for the lack of precision in the statement), but it reminds me of some statistics I found a while back showing that most people breathalysed other the limit after a crash were young while most people caught randomly were old. Suggesting either that old people are less affected or just that young people are so much more likely to crash in the first place.

Or it might suggest that older people are more likely to drink and drive (and thus get caught randomly), and young people more likely to crash (and this be breathalyzed).


I assume this is foreign research given that random breath testing is unlawful in the UK?

[Andy33gmail]

Sorry, yes, that - admittedly I only stated half of what I meant

Edit: And indeed only read half your post!

Honestly, I read this >5 years ago, I remember mentioning it to my Dad while I was still at uni. I'll struggle to find the source

Random breath tests do happen in practice. Cambridge frequently blocks off a major road, the police talk to each driver in turn. If you said something daft or smelled of booze that would be sufficient grounds for the breath test. I honestly can't remember what I read in enough detail to comment

It was quite an amusing conversation though:
"Are you drunk?"
"No" (found it very hard not to laugh!)
"When did you last drink"
"erm ... (pause while I thought) ... last night"
"Ok. Follow the red car out to the right"

[Bryn666]

I assume this is foreign research given that random breath testing is unlawful in the UK?

Having been randomly pulled into a checkpoint a few months ago and breathalysed (I blew 0), was I within my legal rights to refuse a specimen? I doubt I'd have won any friends.

[michael769]

Having been randomly pulled into a checkpoint a few months ago and breathalysed (I blew 0), was I within my legal rights to refuse a specimen? I doubt I'd have won any friends.

Did they explain why they were requiring it in terms of Sect.6 of the Road Traffic Act 1988? Specifically did they explain that it would be an offence to refuse? There is a standard script they recite when it's mandatory.

If not then it was entirely voluntary.

I'd not recommend not cooperating though - while we all like to think we have nothing to hide, few of us could truly stand up to concerted scrutiny (for example are you 100% certain that right now one of your tires is not a teensy wee bit under or over-inflated?). It's generally not wise to poke that particular sleeping dog.

[Bryn666]

Yes, although refusing would make you look as if you were hiding something.

Given I have a deep dislike of drunk driving, I had no problems supply a specimen. I'd favour more random stops of drivers to determine fitness of both driver and vehicle, far preferable to just relying on speed cameras.

[michael769]

You'll get no argument from me on that front.

[PeterA5145]

Given I have a deep dislike of drunk driving, I had no problems supply a specimen.

It's still an abuse of police powers, though. Whatever offence they're suspected of, people still have rights, and the end shouldn't be seen as justifying the means.

[Chris5156]

To bring us back on topic...

Clearly nothing to do with safety, Hounslow presumably needed a bit more cash for this year's budget.

The A406 North Circular is managed by TfL, so it's nothing to do with Hounslow.

It appears to have been implemented because of the bridgeworks which stop hundreds of yards before the 40 signs. Will they revert to the old border when they finish in two years? Unlikely.

https://www.thegazette.co.uk/notice/2118119

You linked to the orders for the new speed limit, which very clearly states that the order will be revoked when works are complete. It owuld have to be as it also bans a number of turns and provides for temporary closures of side roads, which would have to be re-opened once the works are complete.

I also wouldn't automatically assume that TfL are hellbent on reducing speed limits by the back door. They recently increased the Coulsdon Relief Road from 30 to 40mph, and the A13 went up from 40 to 50 a couple of years back.

[Robin]

I also wouldn't automatically assume that TfL are hellbent on reducing speed limits by the back door. They recently increased the Coulsdon Relief Road from 30 to 40mph, and the A13 went up from 40 to 50 a couple of years back.

I wish they'd restore the old 60mph speed limit on the A12 between Hackney Wick and Bow. I never saw an accident in the old days and I used to drive that stretch to and from work five days a week. (It wasn't the A12 then)

[Chris5156]

I also wouldn't automatically assume that TfL are hellbent on reducing speed limits by the back door. They recently increased the Coulsdon Relief Road from 30 to 40mph, and the A13 went up from 40 to 50 a couple of years back.

I wish they'd restore the old 60mph speed limit on the A12 between Hackney Wick and Bow. I never saw an accident in the old days and I used to drive that stretch to and from work five days a week. (It wasn't the A12 then)

Yes, I'd have thought that could at least go up to 50. If you drive it at 50 today you'll be the slowest thing on the road.

The bends at Hackney Wick are reasonable for a 40, and the section immediately south of Bow is as well thanks to the corners and weaving movements, but the stretch between the two is full D3M and nobody takes 40 seriously there.

[DavidNW9]

Going off the same tangent the A40(M) was downgraded so TfL could administer it, and now it's 40 (or less now?) after being a motorway. The road hasn't changed so why has the speed limit?

Does anyone know if the percentage of London cameras on is still about 56%, and whether they still use film or digital, and if that means if too many people go through it may use up the film ? (I have no idea how they work). I think the limit was only shifted yesterday so would have had quite a few others caught on their first time. I'm also disgusted there's no requirement to announce new speed limits. They normally do but clearly optional. How are people supposed to know without a sign?

[Chris5156]

Going off the same tangent the A40(M) was downgraded so TfL could administer it, and now it's 40 (or less now?) after being a motorway. The road hasn't changed so why has the speed limit?

That's due to the deteriorating state of the elevated road structure. Slower traffic puts less strain on joints between sections and reduces the level of vibration.

[DavidNW9]

Blimey, America's riven with elevated highways, we have about two. Wouldn't it be slightly more sensible to spend ('invest') in repairing it? Oh sorry, this is Britain, what was I thinking

[Bryn666]

Yeah but theirs tend to collapse.

The 40 on the Westway is a bit slow. It was of course also 60 originally. The Ringway system presumably was to be mostly this.

[DavidNW9]

My next question, is it true if a camera flashes it's working or do they flash with or without being hooked up or loaded with film? If I know this is the case I won't be left with any false hope of a reprieve.

[Lockwood]

They do sometimes have a flash unit but no camera.

[Truvelo]

The trick with traditional Gatsos is to exceed the limit by at least the ACPO guidelines travelling the opposite way to which the camera is pointing. If it flashes it's a dummy. If it doesn't flash it's either a real camera or an empty box. Unfortunately the cameras on the affected section are both digital so this trick doesn't work.

[Lockwood]

And the real trick is to do that as someone is going the correct way.