M5 Junction 19 Users

[CubanPete]

Anyone else use this junction? Southbound every evening queues 2-8 miles long on the motorway, this leads to many extraordinary / dangerous / idiotic driving manoeuvres. Worse when it is busy...

It has become increasingly bad after the 2012 'improvements'. A lot of this could be simply solved by re balancing the light sequence.

I have been haranguing the various bodies for a while, but if anyone else fancies making their voice heard, this is the list of emails I am currently sending to...

[e-mail] (Liam Fox's secretary, she has been quite communicative)

[e-mail] Main contact
[e-mail] His sidekick, could be boss
[e-mail]
[e-mail]
[e-mail]
[e-mail]
[e-mail]
[e-mail] Ops director
[e-mail]
[e-mail]


and cc'ing

[e-mail]
[e-mail]
[e-mail] Bristol evening Post
[e-mail] North Somerset Times
[e-mail]
[e-mail]
[e-mail]
[e-mail] Chairman of the association of British insurers

[jkh112]

Having witnessed and endured the pain that occurred during the bridge widening to put in the extra lane for the Jct 19 exit I would be surprised if there is much appetite or budget to do anything else major. The issue is the over development of Portishead ahead of the road infrastructure.
I get particularly frustrated as I need to use Jct 19 to exit the motorway but to go on the A369 towards Bristol, yet I am forced to sit in the queue caused by the Portishead route.
I was involved in a similar campaign around the queues for Jct 17 Cribbs Causeway from the South, when the crawler lane was proposed on the hill but with lane 4 ending just short of the junction this was a missed opportunity as lane 1 could have run on to become the exit lane with lane 4 naturally becoming lane 3 past the junction, but no interest from the authorities to consider this even at consultation phase.

Edited by jkh112 on Friday 7th October 07:56

Edited by jkh112 on Friday 7th October 07:58

[TDIfurby]

Is that the Gordano services junction? I am glad I've never seen it like described.

[giltranator]

I am quite fortunate that I come off at J18 although I get still get stuck in it. The most dangerous bit is coming off J18 on a Friday, getting up to where it merges with the M49 and it's stopped with people coming from Wales trying to join the m5 south.

J19 has the capacity to make the slip road two lanes for Portishead, it's two lanes around the roundabout so why can't they make the slip road two lanes also, this would at least remove some of the cars from queuing on the bridge. Would be good if they could widen the portbury hundred too to make it two lanes in both directions. I do think they could do something with the slip road, repaint the road markings and new signage...can't be that expensive surely?

[b0rk]

The J19 lights are MOVA IIRC so demand/flow based rather than traditionally sequenced, the morning flows onto the M5 work well with the improvements moving traffic out of portishead quickly.

The issue to me appears to be that improvements are too efficient at channelling traffic off the M5 and onto the portbury hundreds. The portbury hundreds are basically static/slow moving due to quays avenue and wyndham way being beyond capacity. The solution IMHO is not one for highways agency but North Somerset council highways and the PQC developers. A much more complex and expensive roads solution is needed for portishead to genuinely address the issue which I suspect N Somerset do not have the budget for.

[CubanPete]

I accept that is the theory.

However in the evening, even before the hundred is busy the M5 southbound queues for several miles. There are rarely more than a few cars queuing in the other directions suggesting the MOVA system is pretty unbalanced. When the system was broken a few weeks ago the traffic flowed more freely, and before the 2012 'improvements' were implemented the traffic flowed more freely, though they have improved the morning traffic slightly (I am long gone before the morning traffic is an issue), my other half travels later (7.30) and would argue it doesn't flow very freely.

[CubanPete]

Have a meeting with Highways England in a couple of weeks.

They have acknowledged the junction needs balancing and are going to speak to Skanska about the light sequencing.

[DevonPaul]

CubanPete said:

I accept that is the theory.

However in the evening, even before the hundred is busy the M5 southbound queues for several miles. There are rarely more than a few cars queuing in the other directions suggesting the MOVA system is pretty unbalanced. When the system was broken a few weeks ago the traffic flowed more freely, and before the 2012 'improvements' were implemented the traffic flowed more freely, though they have improved the morning traffic slightly (I am long gone before the morning traffic is an issue), my other half travels later (7.30) and would argue it doesn't flow very freely.

MOVA is an overhyped panacea much beloved of Highways England. It does not work well on roundabouts, as it is a stage based control system rather than phase based. On a standalone crossroads or perhaps even a couple of closely linked junctions then it is fine, which is what it was designed for.

It also copes extremely badly with exit blocking, as it tries to get as much traffic onto the roundabout as it can and if it has nowhere to go it 'sees' the flow drop and switches to a different stage, often just as the one that was running finally gets a gap to go into.

At quiet times you often are stopped at a red on a MOVA roundabout with nothing coming, but which changes when something arrives on the other approach.

However, the biggest limiting factor with the Gordano roundabout is the A369 which is a single lane with a max capacity of (in reality) about 1650-1700 vehicles per hour.

You can do whatever you want with the lights on the roundabout, but when demand exceeds that, you are going to get queues. I suspect at peak times you could run permanent green from the M5 Southbound and it would still queue back.

[CubanPete]

Notes I circulated post meeting.

Basically we need as many people as possible to lobby MPs, otherwise it will be 2025 before they even look at it...



Notes from meeting 15 Nov 2016

We had a positive meeting in which we ran through some of the constraints and issues around the issues regarding M5 Southbound Junction 19. I'd like to thank all attendees, particularly Sean for his hard work.

We covered a lot of items, so hopefully this is a fair report.

The junction was designed in the 1960s, for traffic levels in the 1970s. It is fundamentally under capacity for current traffic levels.
The node between the A369 eastbound and the M5 southbound is the currently primary constraint.
HE are not supporting any further planning requests in this area due to the lack of capacity withing the road network.


Signalling
· The signal have been adjusted to re-balance the roundabout. This has improved things, reducing the queuing from circa 8 miles to about 3 miles and improving motorway traffic flow, and speeding up the queuing. This in an improvement, rather than a solution, the queuing is 'less abysmal' but this is a sticking plaster to a still very under capacity piece of the road network.
o There are still some issues with this, although increased 'green time' the first phase of this only allows a few vehicles through is lost with the subsequent light being out of phase
· North Somerset have adjusted the pedestrian crossing on Wyndham way (these lock the roundabout at the end of the Portbury Hundred), which causes traffic to tail back to try and increase help reduce roundabout egress delays caused by slow moving traffic on the Portbury Hundred
· The sensors used in the MOVA signalling are located just 40 metres in front of the lights (i.e. the system isn't set-up to balance 8 mile traffic queues)
· Due to the design with the M49 join becoming the J19 slip road, there is no 'back of the queue' available, this is a source of many of the 'frustrated driver' dangerous manoeuvres seen (there is plenty of poor driving too!).

Safety
· Accidents are only recorded for road improvement statistics if there is death or major injury, explaining the disparity between observed and recorded accidents.
· The statistics leading up to the junctions aren't significantly worse than other junctions within the area. This accident count was described as 'surprisingly few' and was a shock to all attendees. I hypothesise this is due to
o Traffic only being able to travel at very slow speeds for much of the duration
o Hyper-vigilant driving due to the traffic conditions
o Luck; there will be a very nasty accident in the lead up to this junction unless improvements are made.
· After suggesting Highways contact the ABI for additional crash data, it transpires that this has been an ongoing request for a couple of years. The ABI are reticent about supplying anonymised data, despite this being for the public good, and saving their members money in payouts. Other data sources are being investigated.

What next?
· There is some lining changes planned this financial year.
· There is a study to look at removing the service filter island to allow two lanes of traffic to exit to Portishead (due to complete July). Funding is required to take this any further than this stage. This needs to be pressed for otherwise, it will be 2025 strategic review...
· West of England Local Enterprise Partnership makes some pretty strong statements re the investment required in the transport network
http://www.westofenglandlep.co.uk/assets/files/Tra...

In summary, HE and North Somerset are doing what they can, however the current road network is under capacity, and investment is needed. It won't be long before the queues will be back to the M4 interchange and gridlocking Bristol.


Ione, please could you ask Dr Fox to:
· Lobby the insurance industry / ABI to provide anonymised accident data that we can use for road improvements
· Lobby Chris Grayling that some of the available / promised money for infrastructure improvements is directed towards this area
o Junction improvement
o Move local traffic from shared motorway junction
o Alternative route to cross the Avon (the Avonmouth bridge is the only available route without travelling into central Bristol)
o Accelerate activity on re-opening the Portishead - Bristol railway line
o Affordable public transport (£7 for a bus into Bristol, when they actually turn up, this is why people drive)

[cptsideways]

Just try turning the traffic lights off at the roundabout, my bet is flow would improve massively.

[CubanPete]

cptsideways said:

Just try turning the traffic lights off at the roundabout, my bet is flow would improve massively.

It might. They turn off the lights at J14 (Falfield) when it is busy as they are unable to cope with the flow. Part time lights that only operate during quiet periods!

[CubanPete]

Updated list of who to lobby (post meeting with Highways England)!

[e-mail]
[e-mail]
[e-mail]
[e-mail];

[giltranator]

giltranator said:

I am quite fortunate that I come off at J18 although I get still get stuck in it. The most dangerous bit is coming off J18 on a Friday, getting up to where it merges with the M49 and it's stopped with people coming from Wales trying to join the m5 south.

J19 has the capacity to make the slip road two lanes for Portishead, it's two lanes around the roundabout so why can't they make the slip road two lanes also, this would at least remove some of the cars from queuing on the bridge. Would be good if they could widen the portbury hundred too to make it two lanes in both directions. I do think they could do something with the slip road, repaint the road markings and new signage...can't be that expensive surely?

It would seem the highways agency have taken note! They have tweeted this morning that there is a new road layout for the sliproad. Of the three lanes on the J19 sliproad, the left lane is for the services with the other two now for Portishead.

Hopefully people will realise this on their commute home this evening

[jkh112]

So now those of use going into Bristol on the A369 will now have to wait in the queue all the way up the sliproad as well as on the bridge.
Bloody townies moving into Portishead!

[williredale]

giltranator said:

It would seem the highways agency have taken note! They have tweeted this morning that there is a new road layout for the sliproad. Of the three lanes on the J19 sliproad, the left lane is for the services with the other two now for Portishead.

Hopefully people will realise this on their commute home this evening

Is that today? I drove through yesterday late afternoon and commented to the OH that they hadn't made any changes yet.

[scrumpy]

CubanPete said:

It might. They turn off the lights at J14 (Falfield) when it is busy as they are unable to cope with the flow. Part time lights that only operate during quiet periods!

I completely agree! At quiet times you can sit for ages waiting for the J14 lights to change when hardly any traffic comes through the junction. They are a complete nonsence and completely unnecessary.