Types of VMS

[ManomayLR]

Ugh, what a terrible (and unsafe!) use of contradictory signs there.

The little signs, showing three "lane closing" signs (looking like a no-through-route sign), are correct. They give the distance to the lane closure, and allow people to move over at their own pace.

However, the MS4s are showing three red Xes! So they officially and legally closed the lane well before the actual taper. This is clearly a problem, given that there was no need to close the lanes that far back, as it's likely to reduce compliance with red Xes, which are legally binding and safety-critical.

In my opinion, they could have both types but it has to be synced. If the little ones with the wickets say 800 yards, then there should be white arrow on the mandatory signs until 800 yards later. After the distance on the advisory wickets is up, then the white arrow should change to red X on the mandatory signals. Effectively it means "you may not continue more than 800 yards in this lane" and if the closure is till ahead then that means white arrows should be displayed on the MS4 / Gantry signs until the 800 yards on the wickets becomes 0 yards, and then that means "you can not proceed any further in this lane" which means the same as the red X.

[ais523]

Well, you'd at least want the "move over into leftmost lane" diagonal arrow on the MS4s (which is the way you indicate that the lane's still open but about to close, when you don't have a distance marker available). An upwards arrow would be misleading.

I can also see an argument for a proper red-X close on the rightmost two lanes at that point (you don't want to merge three lanes of traffic into 1). So maybe up arrow, diagonal arrow, X, X is correct on the MS4 (with the smaller signs, whatever they're called, giving the exact distance to the full three-lane closure).

[Bendo]

Ugh, what a terrible (and unsafe!) use of contradictory signs there.

The little signs, showing three "lane closing" signs (looking like a no-through-route sign), are correct. They give the distance to the lane closure, and allow people to move over at their own pace.

However, the MS4s are showing three red Xes! So they officially and legally closed the lane well before the actual taper. This is clearly a problem, given that there was no need to close the lanes that far back, as it's likely to reduce compliance with red Xes, which are legally binding and safety-critical. (This is particularly annoying because at least the TSRGD allows the "lane closing" no-through-route-shaped sign to be used on an MS4, having a similar functionality to a red X without being legally binding, and thus letting people move over at their own pace; it would be silly if the MS4s have a particular sign approved for this situation and yet are incapable of showing them.)

We can see from the video that vehicles are ignoring the red Xes. Given the actual reason for them, they presumably concluded that it was safe to do so. So if we aren't confining the use of red Xes to safety-critical situations, we can expect them to also be widely ignored in the situations where their safety meaning is actually necessary.

(For what it's worth, I believe that proper selection of advisory versus mandatory signs would be a cheap and effective way to reduce accidents. If you place a mandatory sign in a place where it's unnecessary, it tends to get ignored, and then you have wildly differing speeds and/or lane disciplines between the people who obey the law and follow it, and the people who obey their road sense and ignore it. If you place an advisory sign in such a situation, the traffic acts in a more uniform way, which is safer.)

It appears this isn't a one off problem. Came across the exact the scenario as in the video on M5 s/b approaching J6, MS4 showing all lanes closed except L4 and the little signs at the side indicating they aren't legally closed by closing x yards ahead.

[nowster]

This happens a lot with gantry MS1 type VMSes too. The red X is set well before the actual closure, contradicting the verge-side metal signs.

[Jeni]

This happens a lot with gantry MS1 type VMSes too. The red X is set well before the actual closure, contradicting the verge-side metal signs.

It's my understanding that they're only used until the works are fully set out, then should be turned off?

[nowster]

This happens a lot with gantry MS1 type VMSes too. The red X is set well before the actual closure, contradicting the verge-side metal signs.

It's my understanding that they're only used until the works are fully set out, then should be turned off?

That might be the intention, but in practice...

[ManomayLR]

This happens a lot with gantry MS1 type VMSes too. The red X is set well before the actual closure, contradicting the verge-side metal signs.

It's my understanding that they're only used until the works are fully set out, then should be turned off?

I think that’s a bad idea. The lane-diversion sequence needs to be in place on the electronic signs at all times to forewarn travelers of the closure. This is especially true where the entire motorway is closed. The white arrow and red X symbols should be used in sequence to safely “zip-merge” vehicles into the open lanes or slip-roads.

[DB617]

I don't think it helps that some of the UI stuff in the RCCs, for MS1s especially, is not very user friendly. It must take a lot of skill in visualisation and system knowledge to translate a series of numerical sign references into a coherent set of successive gantries with the correct feed-in arrows. Get one wrong and you make things worse instead of better. The lack of usability probably contributes to neglect in some areas - MS1s are barely used around Cardiff, and I'm pretty sure the section of the A4232 that falls under Cardiff Council has been allowed to lose much of its MS1 kit to lack of maintenance. Those guys need all the help they can get.

[ManomayLR]

I don't think it helps that some of the UI stuff in the RCCs, for MS1s especially, is not very user friendly. It must take a lot of skill in visualisation and system knowledge to translate a series of numerical sign references into a coherent set of successive gantries with the correct feed-in arrows. Get one wrong and you make things worse instead of better. The lack of usability probably contributes to neglect in some areas - MS1s are barely used around Cardiff, and I'm pretty sure the section of the A4232 that falls under Cardiff Council has been allowed to lose much of its MS1 kit to lack of maintenance. Those guys need all the help they can get.

The upgrade to MS4 might change things???

[DB617]

I don't think it helps that some of the UI stuff in the RCCs, for MS1s especially, is not very user friendly. It must take a lot of skill in visualisation and system knowledge to translate a series of numerical sign references into a coherent set of successive gantries with the correct feed-in arrows. Get one wrong and you make things worse instead of better. The lack of usability probably contributes to neglect in some areas - MS1s are barely used around Cardiff, and I'm pretty sure the section of the A4232 that falls under Cardiff Council has been allowed to lose much of its MS1 kit to lack of maintenance. Those guys need all the help they can get.

The upgrade to MS4 might change things???

I hope so. Sadly certain regions which originally received then-good kit such as the overhead MS1s and VMS on the A4232 over Cardiff Bay, will not have it replaced with MS4, ie most non-trunk dual carriageways some of which could benefit hugely from the information provided. Cardiff Council has a lot of old non-standard matrix signs and somehow have maintained a number of prismatic signs on roads connecting to the PDR. On the trunk part of the road, the Trunk Road Agent has now found themselves a 'temporary' non-standard VMS on a silly trailer to reduce the number of accidents caused by people ploughing into Culverhouse Cross at 75mph when there's traffic hanging off the slip road.

Is there an intention to replace the median MS1 posts with just MS4s? The median signals are probably all ancient at this point and surely lose compatibility or become uneconomical to maintain eventually.

On another related note, what on earth are the small square closely spaced display units on the M5 south of J4A? They look a lot like how I'd imagine the future expressway 'technology' to look. They're almost the modern 'smart' version of the original dot matrix.

[Bendo]

On another related note, what on earth are the small square closely spaced display units on the M5 south of J4A? They look a lot like how I'd imagine the future expressway 'technology' to look. They're almost the modern 'smart' version of the original dot matrix.

Are they not the ones discussed in this thread earlier viewtopic.php?f=1&t=15130&start=20#p876903, the ones that frequently contradict lane closures shown on the MS4s.

[DB617]

Yes, those. My bad. Shame they aren't used properly - my first thought is they were added onto the design but the HE RCC never actually knew what to use them for or how.

[jusme]

I sometimes wonder if these could be used as VSL repeaters, at least that way they would have been of some use in their lifetime. They're red/white, so could do a good impression of a valid limit sign. Just a simple firmware upgrade and some paperwork to make them legal I gusess ( fsvo "simple" )

[Conekicker]

I sometimes wonder if these could be used as VSL repeaters, at least that way they would have been of some use in their lifetime. They're red/white, so could do a good impression of a valid limit sign. Just a simple firmware upgrade and some paperwork to make them legal I gusess ( fsvo "simple" )

No, they cannot be used as VSL repeaters, they are only authorised for use to display roadwork triangles or wicket signs.

They are also most definitely not under the control of the HE RCC. Rather they are operated by the maintaining contractor for the Area, being solely for use to warn of roadwork lane closures ahead. Some sets are positioned in advance of exit slips, for use when a link is to be fully closed, so potentially they could be used for incidents requiring a full closure - with the rider that it would be difficult to get a crew into position to deploy the coning in heavy traffic.

Having these signs accessed by the RCC could result in them being turned off (or on) at the wrong time during roadworks, hence the "air gap" in who controls them.

[DB617]

Was it officially judged to be a value for money move to have them installed? From what I saw the newest scheme on the M1 at Nottingham hasn't got any.

[Conekicker]

It's not a case of value for money, it's a case of not putting men out on foot deploying static signs in the four lane high speed environment that is an ALR.

There was a suggestion that the MS4s could do the job, but as they are few and far between, with no back up power supply and potentially vulnerable to being retasked to display other messages by RCC operators, the sensible decision was (eventually) taken to install the ROTTMs.

I'm not familiar with the Nottingham scheme but if they've been omitted, someone will come to regret that decision I fear.

[ManomayLR]

Well to bring it up-to-date, what kind of VMS is this, and what does it show? Seem to be a lot of them on M6 J10-13 ALR section. I've never been (un)lucky enough to see them lit:



https://www.google.co.uk/maps/@52.70234 ... !1e1?hl=en

Yay, finally saw a brace of these in action - M6 J17-16 s/b (being ignored, of course):

https://youtu.be/-yd6YiWp7Mc

Cute little things, if a little shy

The control room operator needs a medal. Using both MS4 and ROTTMs really managed the closure well.

[ManomayLR]

Is there an intention to replace the median MS1 posts with just MS4s? The median signals are probably all ancient at this point and surely lose compatibility or become uneconomical to maintain eventually.

The central reserve MS1s are not paired with motorway incident/queue detection and automatic signalling - so all the legends have to be set manually. LEDs are used in modern installations but these have been in use since 1968.

MS3s and MS4s, however, are paired with motorway incident/queue detection and automatic signalling - and MS4s can be used on smart motorways too.

Replacing central reserve MS1s with MS3s happened on the M1 in the late 90s and early 2000s.

In less busy areas it may not be justified as a communications upgrade may involve running new cabling down the motorway and/or resurfacing to add traffic detection loops or radar technology for automatic incident/queue detection.

But now you mostly see a replacement only where a smart motorway scheme is involved (such as the current M4 J3-8/9. J8/9-12 already has MS4s but they are likely to be taken down and modified for smart technology, if not replaced. Cantilevers may be reused though, I wouldn't know for sure).

[ais523]

The control room operator needs a medal. Using both MS4 and ROTTMs really managed the closure well.

If I understand correctly, that was two different control room operators (the ROTTMS system is under direct control of the contractors, the MS4 system controlled by Highways England).

We're kind-of fortunate that they agreed about what lanes to show as closed! (From experience, that doesn't always happen.)

[DB617]

The control room operator needs a medal. Using both MS4 and ROTTMs really managed the closure well.

If I understand correctly, that was two different control room operators (the ROTTMS system is under direct control of the contractors, the MS4 system controlled by Highways England).

We're kind-of fortunate that they agreed about what lanes to show as closed! (From experience, that doesn't always happen.)

Technically though, they don't quite agree; the HE signals show three lanes as 'you must not pass in this lane' while the contractor signals are displaying 'lane closed ahead'. According to the ROTTMS the Audi and HGV were just merging in turn, whereas on the MS4 they were committing an offence.