I believe the tunnel crossovers have a low design speed due to the large lateral shift. The US/Canada arrows are like many mVMS in that the light output is at the max on belief than the more like a Christmas tree the better. It may work, but at least the changes should mean its not an increased safety risk.Conekicker wrote: ↑Sat Jan 08, 2022 23:10Then it must be very risky indeed at that tunnel if they are showing a 40 (but not starting where Chapter 8 says it should). If it's that risky, why are they using untried kit. And, yes, I know it's been tried overseas but the signs on the barriers they use there are vastly different to the ones used over here.Bomag wrote: ↑Sat Jan 08, 2022 15:16The number of times I have had to remind practitioners that if there is sufficient risk to justify a speed limit, it not a relaxation scheme.Conekicker wrote: ↑Sat Jan 08, 2022 09:19
At least the video seems to be proposing both nearside and offside signs, so drivers should be better informed of the presence of the taper ahead than tends to be the case with overnight relaxation tapers on most of the network these days. Having said that, all this kit will be very expensive, especially if this is a genuine trial and not a "we've installed it at great expense and if there are no incidents or KSI we'll call it a success because we haven't set aside the cash to remove it if it's a failure" trial.
Someone needs to remind the bozos up in 14 about imposing a 50 for overnight closures then leaving the signs up during daylight with an otherwise unobstructed carriageway. The bozos.
Edit - The barrier has been crash tested, although looking at the video, not with the same kit as installed at the tunnel, which makes the test a bit on the questionable side:
https://www.youtube.com/watch?v=kY_gExNJn_E
This apparently is what they look like in Canada, totally different and far more visible than the UK iteration:
http://www.versilis.com/fr/realisations ... 1-ontario/
"Swift Gates" to be trialled replacing cone tapers
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Re: "Swift Gates" to be trialled replacing cone tapers
Re: "Swift Gates" to be trialled replacing cone tapers
This all looks extremely similar to the system that's been in use on the I-5 reversible express lanes in Seattle for decades now. While I haven't seen it in use in construction zones, it seems like a bit of a stretch for them to be claiming this is a massively innovative new thing.
Re: "Swift Gates" to be trialled replacing cone tapers
I believe the kit at the Hindhead Tunnel can only show NSL or 40 - there are no other limits available on the prism signs. 40 is presumably deemed a safe speed when they are operating one tunnel with two-way running, but that means 40 is the only speed other than NSL that can be used.Conekicker wrote: ↑Sat Jan 08, 2022 23:10Then it must be very risky indeed at that tunnel if they are showing a 40 (but not starting where Chapter 8 says it should). If it's that risky, why are they using untried kit.
Chris
Roads.org.uk
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Re: "Swift Gates" to be trialled replacing cone tapers
Thank you for the comparison. The Seattle express lanes have long fascinated me, ever since I first saw them on my first day ever visiting the USA, many decades ago. The way I-5 had been woven right through the city is still, I think, one of the most enterprising sections of the whole US Interstate system.jay8g wrote: ↑Sun Jan 09, 2022 08:35 This all looks extremely similar to the system that's been in use on the I-5 reversible express lanes in Seattle for decades now. While I haven't seen it in use in construction zones, it seems like a bit of a stretch for them to be claiming this is a massively innovative new thing.
The way the moveable barriers have been done in Seattle is of course far better than this A3 experiment, fully integrated into the centre divider continuous Jersey Barrier when retracted instead of plonked on a hard, sharp-cornered concrete block a few feet from high speed passing traffic.
Re: "Swift Gates" to be trialled replacing cone tapers
Well the swift gate in this picture at Hindhead looks low enough that very few cars could get under it. a go kart might but we dont see many of those on strategic roads.Chris5156 wrote: ↑Sat Jan 08, 2022 10:46They are weirdly high up compared to most TTM. That's because they have to swing out over the top of the central reserve crash barrier, so the height is inevitable, but I do keep looking at them as I go past and thinking that a low-slung sports car would quite happily just pass underneath them. I'm not yet convinced that an ordinary car wouldn't make it underneath too.Conekicker wrote: ↑Sat Jan 08, 2022 09:19All of the assemblies seem to be at a height that could be out of the beam of dipped headlights, which might make life interesting for some drivers.
https://assets.publishing.service.gov.u ... tecrop.jpg
As I understand it these are only intended to be used in a small number of fixed locations not to replace cones in general. Given that a number of Highways Maintenance workers are injured, sometimes seriously or fatally every year this seems reasonable especially if as with level crossing barrier they are frangible if struck which the crash cushion vehicles currently used are definitely not.
https://www.roadsafety.co.uk/products-s ... h-cushions
Re: "Swift Gates" to be trialled replacing cone tapers
Right behind each barrier is a hard, sharp-cornered concrete block a few feet from high speed passing traffic.WHBM wrote: ↑Sun Jan 09, 2022 09:34
The way the moveable barriers have been done in Seattle is of course far better than this A3 experiment, fully integrated into the centre divider continuous Jersey Barrier when retracted instead of plonked on a hard, sharp-cornered concrete block a few feet from high speed passing traffic.
https://www.google.com/maps/@47.7050421 ... 6656?hl=en
The reality is nothing is 100% safe, humans will always find a way to win a Darwin award.
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Re: "Swift Gates" to be trialled replacing cone tapers
"Far better" and "fully integrated" as in a hard sharp-cornered block of concrete much closer to high speed passing traffic when the gate is in its retracted position (presumably for the majority of the time)?WHBM wrote: ↑Sun Jan 09, 2022 09:34..The way the moveable barriers have been done in Seattle is of course far better than this A3 experiment, fully integrated into the centre divider continuous Jersey Barrier when retracted instead of plonked on a hard, sharp-cornered concrete block a few feet from high speed passing traffic.
Why would anyone design-in this hazard by reducing the height of the barrier and providing a square end?
https://goo.gl/maps/bUKZw9aAE1QsXUeB6
Re: "Swift Gates" to be trialled replacing cone tapers
I believe the barriers on I-5 date back all the way to the original 1960s construction, so people probably weren't thinking about those things as much back then. Here's a newer, better, but abandoned example (which I believe was put in for that ramp to be temporarily used for airport construction).
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Re: "Swift Gates" to be trialled replacing cone tapers
Only "better" in that the hazard of a square ended barrier is replaced by metal sections attached to the face of the barrier intruding into the roadspace for an unsuspecting vehcle to strike.jay8g wrote: ↑Mon Jan 10, 2022 01:56 I believe the barriers on I-5 date back all the way to the original 1960s construction, so people probably weren't thinking about those things as much back then. Here's a newer, better, but abandoned example (which I believe was put in for that ramp to be temporarily used for airport construction).
Re: "Swift Gates" to be trialled replacing cone tapers
If you look at an older version of GSV they show that am intersection was closed thereRichardA35 wrote: ↑Mon Jan 10, 2022 09:24 Only "better" in that the hazard of a square ended barrier is replaced by metal sections attached to the face of the barrier intruding into the roadspace for an unsuspecting vehcle to strike.
2008
https://www.sabre-roads.org.uk/maps/ind ... 8,-5.60174,
2021
https://www.google.com/maps/@47.4477339 ... 8192?hl=en
The barrier is actually designed to absorb the shock of a collision, the space between the armco is filled with plastic bags of fluid to absorb an end on impact.
https://www.google.com/maps/@47.447605, ... 8192?hl=en
This is quite common in the USA, they used something similar at some of the intersections on OH-315 in Columbus.
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Re: "Swift Gates" to be trialled replacing cone tapers
I fear I have not been clear - it is not the arrangement of the slip roads nor the arrangement of two barriers nor the terminal, but the swing out arm with a reasonably heavy steel section that is shown parked in front of the rear barrier, which, during its working life without the front barrier, would have provided a significant hazard for passing vehicles.KeithW wrote: ↑Mon Jan 10, 2022 14:07If you look at an older version of GSV they show that am intersection was closed thereRichardA35 wrote: ↑Mon Jan 10, 2022 09:24 Only "better" in that the hazard of a square ended barrier is replaced by metal sections attached to the face of the barrier intruding into the roadspace for an unsuspecting vehcle to strike.
2008
https://www.sabre-roads.org.uk/maps/ind ... 8,-5.60174,
2021
https://www.google.com/maps/@47.4477339 ... 8192?hl=en
The barrier is actually designed to absorb the shock of a collision, the space between the armco is filled with plastic bags of fluid to absorb an end on impact.
https://www.google.com/maps/@47.447605, ... 8192?hl=en
This is quite common in the USA, they used something similar at some of the intersections on OH-315 in Columbus.
Re: "Swift Gates" to be trialled replacing cone tapers
RichardA35 wrote: ↑Mon Jan 10, 2022 14:16 I fear I have not been clear - it is not the arrangement of the slip roads nor the arrangement of two barriers nor the terminal, but the swing out arm with a reasonably heavy steel section that is shown parked in front of the rear barrier, which, during its working life without the front barrier, would have provided a significant hazard for passing vehicles.
The swing out arm and barrier is on a slip road that has been closed and abandoned for a long time, to hit it the driver would have to get past the Jersey Barrier.
https://www.google.com/maps/@47.4478036 ... 8192?hl=en
The whole road and bridge (South 176th Street) has been closed in fact if you look at the top of the intersection.
https://www.google.com/maps/@47.4451155 ... 8192?hl=en
If you we able to go up that slip road and turn left you would find yourself on the SeaTac airport runway perimeter road. I believe that access was closed when the airport was expanded.
https://www.google.com/maps/@47.4454216 ... !1e3?hl=en
Re: "Swift Gates" to be trialled replacing cone tapers
I agree the placement of the steel vertical member that forms part of this is a bad idea, that's at the right height to cut into an errant vehicle running down the concrete barrier, that's an instant passenger serious injury there in a right hand drive environment.RichardA35 wrote: ↑Mon Jan 10, 2022 14:16I fear I have not been clear - it is not the arrangement of the slip roads nor the arrangement of two barriers nor the terminal, but the swing out arm with a reasonably heavy steel section that is shown parked in front of the rear barrier, which, during its working life without the front barrier, would have provided a significant hazard for passing vehicles.KeithW wrote: ↑Mon Jan 10, 2022 14:07If you look at an older version of GSV they show that am intersection was closed thereRichardA35 wrote: ↑Mon Jan 10, 2022 09:24 Only "better" in that the hazard of a square ended barrier is replaced by metal sections attached to the face of the barrier intruding into the roadspace for an unsuspecting vehcle to strike.
2008
https://www.sabre-roads.org.uk/maps/ind ... 8,-5.60174,
2021
https://www.google.com/maps/@47.4477339 ... 8192?hl=en
The barrier is actually designed to absorb the shock of a collision, the space between the armco is filled with plastic bags of fluid to absorb an end on impact.
https://www.google.com/maps/@47.447605, ... 8192?hl=en
This is quite common in the USA, they used something similar at some of the intersections on OH-315 in Columbus.
There must be a happy medium between the US non-passive model and the UK lets have huge concrete blocks behind a working width (hopefully) model.
Bryn
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She said life was like a motorway; dull, grey, and long.
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Terminally cynical, unimpressed, and nearly Middle Age already.
She said life was like a motorway; dull, grey, and long.
Blog - https://showmeasign.online/
X - https://twitter.com/ShowMeASignBryn
YouTube - https://www.youtube.com/@BrynBuck
- RichardA35
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Re: "Swift Gates" to be trialled replacing cone tapers
I fear I have not been clear enough again. When the slip road was open, in operation, with traffic running in the lane nearest to the barrier, without the second line of barrier present and the arms were present in front of the barrier, they represented a hazard to the driver which would not be acceptable in the UK.KeithW wrote: ↑Mon Jan 10, 2022 15:43RichardA35 wrote: ↑Mon Jan 10, 2022 14:16 I fear I have not been clear - it is not the arrangement of the slip roads nor the arrangement of two barriers nor the terminal, but the swing out arm with a reasonably heavy steel section that is shown parked in front of the rear barrier, which, during its working life without the front barrier, would have provided a significant hazard for passing vehicles.
The swing out arm and barrier is on a slip road that has been closed and abandoned for a long time, to hit it the driver would have to get past the Jersey Barrier.
https://www.google.com/maps/@47.4478036 ... 8192?hl=en
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Re: "Swift Gates" to be trialled replacing cone tapers
It's a long time ago but IIRC the WW of a concrete barrier is measured as the distance the striking vehicle oversails the barrier, so the UK model should be outside.Bryn666 wrote: ↑Mon Jan 10, 2022 15:49
I agree the placement of the steel vertical member that forms part of this is a bad idea, that's at the right height to cut into an errant vehicle running down the concrete barrier, that's an instant passenger serious injury there in a right hand drive environment.
There must be a happy medium between the US non-passive model and the UK lets have huge concrete blocks behind a working width (hopefully) model.
Re: "Swift Gates" to be trialled replacing cone tapers
Runway 34L at Seatac was opened in 1970 which is when that intersection would have been blocked.RichardA35 wrote: ↑Mon Jan 10, 2022 16:03 I fear I have not been clear enough again. When the slip road was open, in operation, with traffic running in the lane nearest to the barrier, without the second line of barrier present and the arms were present in front of the barrier, they represented a hazard to the driver which would not be acceptable in the UK.
So that slip road would have been in use the 1960's when we were using pretty much nothing except a centre strip of Armco and plastic cones placed by hand. I would bet good money that the barriers date back to the construction of the runway and the barriers there to restrict access.
As a point of comparison I present the A1(M) Darlington bypass which is still pretty much as built.
https://www.google.co.uk/maps/@54.59467 ... 8192?hl=en
Run off the edge here and the welcome you get is a ditch and trees. Trust me you do not want to hit a tree.
- RichardA35
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Re: "Swift Gates" to be trialled replacing cone tapers
....and there are lots of examples of difference that can be pointed to all over this country and others.KeithW wrote: ↑Mon Jan 10, 2022 17:28Indeed but that would have been the 1970's when we were using pretty much nothing except a centre strip of Armco and plastic cones placed by hand. As a point of comparison I present the A1(M) Darlington bypass which is still pretty much as built.RichardA35 wrote: ↑Mon Jan 10, 2022 16:03 I fear I have not been clear enough again. When the slip road was open, in operation, with traffic running in the lane nearest to the barrier, without the second line of barrier present and the arms were present in front of the barrier, they represented a hazard to the driver which would not be acceptable in the UK.
https://www.google.co.uk/maps/@54.59467 ... 8192?hl=en
Run off the edge here and the welcome you get is a ditch and trees. Trust me you do not want to hit a tree.
However, even in the 1980's we didn't put things deliberately in front of barriers (other than small diameter signposts) as they tended to get crashed into.
The poster who raised this installation claimed it as "better".
I disagree.
Re: "Swift Gates" to be trialled replacing cone tapers
On that we can agree.RichardA35 wrote: ↑Mon Jan 10, 2022 17:40 ....and there are lots of examples of difference that can be pointed to all over this country and others.
However, even in the 1980's we didn't put things deliberately in front of barriers (other than small diameter signposts) as they tended to get crashed into.
The poster who raised this installation claimed it as "better".
I disagree.
Re: "Swift Gates" to be trialled replacing cone tapers
I'm honestly not sure I understand the concern here, either with the SeaTac design (which appears to be breakaway and also folds close enough to the jersey barrier that you'd have to ride up on the sloped section to hit it, at least before the arms started failing) or the UK design (which is well behind the guardrail from what I can see). Clearly, the UK standards for these things are way more strict than the ones I'm used to!
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Re: "Swift Gates" to be trialled replacing cone tapers
"Well behind" - you need to understand the concept of "Working width".jay8g wrote: ↑Mon Jan 10, 2022 20:14 I'm honestly not sure I understand the concern here, either with the SeaTac design (which appears to be breakaway and also folds close enough to the jersey barrier that you'd have to ride up on the sloped section to hit it, at least before the arms started failing) or the UK design (which is well behind the guardrail from what I can see). Clearly, the UK standards for these things are way more strict than the ones I'm used to!
https://www.hwilliams.co.uk/wp-content/ ... une-07.pdf
Patience is not a virtue - it's a concept invented by the dozy beggars who are unable to think quickly enough.