Incorrect overhead motorway signage

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roadphotos
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Incorrect overhead motorway signage

Post by roadphotos »

Is it just me or do some of our overhead motorway signs filter traffic into the wrong lanes. I have driven past a number of these overhead signs that appear to be incorrect. Some are difficult to explain but I'll have a go. The first one is when traveling on the M6 heading east out of Birmingham you come to the junction for the M42 and turn left onto the 2 lane carriageway which leads to the M42 all the overhead signage says lane 1 for M42 north and lane 2 for M42 south but when you get to the point where the 2 lanes split lane 1 appears to widen and split into both directions. In other words traffic can use lane 1 for both M42 north and M42 south but the overhead signs say otherwise. This also means that traffic heading for the M42 south in lane 2 could have stayed in lane 1 all along and has to get back over to lane 1 after the split. It's hard to explain but the overhead signs are definitely incorrect. Another example is the M25 on approach to junction 23. When traveling west on the 4 laned M25 the overhead signs say that lane 1 is for the A1 towards London and the A1081 and that you have to carry on in lane 2 for the A1(M) towards Hatfield so lane 1 takes traffic onto the slip road and you have to stay in lane 2 on the M25 mainline and then take the next slip for the A1(M) towards Hatfield but the 2 routes rejoin once you are on the slip road which looks ok because the left lane is for the A1 towards London and the right lane is for the A1(M) towards Hatfield, it's only when you get halfway down the slip road that the 2 lanes widen to 3 lanes but it's the left lane that widens and the middle lane then becomes a lane for the A1(M) north towards Hatfield which means that anyone that had wanted the A1(M) could have stayed in the left lane all along. Also anyone in a slow moving vehicle who had read the overhead signs would end up in the right hand lane on approach to the junction when they should be in the middle lane as there are 2 lanes for the A1(M). Apologies if I haven't explained this very well but I was wondering if anyone had any other examples of this. Also can anyone show me some pictures of my these incorrect signs at junctions as I'm not sure how to put them up myself.
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Big L
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Re: Incorrect overhead motorway signage

Post by Big L »

The M6 M42 one is a fairly recent change.
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David349
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Re: Incorrect overhead motorway signage

Post by David349 »

The split on the M42 Northbound at Junction 7 always frustrates me, as I frequently am trying to get onto the M6 Southbound

https://www.google.co.uk/maps/@52.47061 ... 312!8i6656

The fact the the M6 (South) is listed on the sign for the M42 means that it's very easy for people to go sailing past the actual exit 1/2 a mile later - I realise it's done to avoid confusion with the M6 Northbound diverge, but really all that is needed is for the M6 (South) to be deleted from the right hand panel and it'll work fine given the next gantry along makes it clear which way to go for which direction.

I've been trying to teach my partner (who passed fairly recently) to read the direction signs and memorise routes rather than follow my directions and it's taken 3 trips through for them to just learn this quirk - you frequently find drivers cutting across quite late further down so it can't just be us!

Additionally, while I know that the M6 South is what I am aiming for, there are numerous points round here where the concept of North/South is actually more of an East/West orientation and it can be confusing- very ocasionally I have to double check with myself that I am taking the right exit as there are a lot of choices (especially coming the other way) so good signage is vital!
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David349
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Re: Incorrect overhead motorway signage

Post by David349 »

roadphotos wrote: Fri Jun 22, 2018 22:25 . Also anyone in a slow moving vehicle who had read the overhead signs would end up in the right hand lane on approach to the junction when they should be in the middle lane as there are 2 lanes for the A1(M). .
I try to avoid being anywhere near here during the rushour, but I imagine this might be done to split the flows of traffic properly - if either the approach for the A1 south or the A1(M) is snarled up, having the traffic split would still allow the other lane to flow properly.
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Stevie D
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Re: Incorrect overhead motorway signage

Post by Stevie D »

roadphotos wrote: Fri Jun 22, 2018 22:25 Is it just me or do some of our overhead motorway signs filter traffic into the wrong lanes. I have driven past a number of these overhead signs that appear to be incorrect. Some are difficult to explain but I'll have a go. The first one is when traveling on the M6 heading east out of Birmingham you come to the junction for the M42 and turn left onto the 2 lane carriageway which leads to the M42 all the overhead signage says lane 1 for M42 north and lane 2 for M42 south but when you get to the point where the 2 lanes split lane 1 appears to widen and split into both directions. In other words traffic can use lane 1 for both M42 north and M42 south but the overhead signs say otherwise. This also means that traffic heading for the M42 south in lane 2 could have stayed in lane 1 all along and has to get back over to lane 1 after the split. It's hard to explain but the overhead signs are definitely incorrect. Another example is the M25 on approach to junction 23. When traveling west on the 4 laned M25 the overhead signs say that lane 1 is for the A1 towards London and the A1081 and that you have to carry on in lane 2 for the A1(M) towards Hatfield so lane 1 takes traffic onto the slip road and you have to stay in lane 2 on the M25 mainline and then take the next slip for the A1(M) towards Hatfield but the 2 routes rejoin once you are on the slip road which looks ok because the left lane is for the A1 towards London and the right lane is for the A1(M) towards Hatfield, it's only when you get halfway down the slip road that the 2 lanes widen to 3 lanes but it's the left lane that widens and the middle lane then becomes a lane for the A1(M) north towards Hatfield which means that anyone that had wanted the A1(M) could have stayed in the left lane all along. Also anyone in a slow moving vehicle who had read the overhead signs would end up in the right hand lane on approach to the junction when they should be in the middle lane as there are 2 lanes for the A1(M). Apologies if I haven't explained this very well but I was wondering if anyone had any other examples of this.
It's quite common that signs on the mainline don't get traffic in the right lane for the junction at the end of the sliproad.

There could be some excuse for it at South Mimms. If A1(M)(N) was signed across lanes 1 and 2 then it's quite likely that lane 1 would get snarled up and would delay A1(S) traffic unnecessarily. If that is the case then the problem is the lane markings on the slip road, and it would be resolved by splitting the right-hand lane instead of the left-hand lane. Similarly, at the M6/M42 junction, the initial lane allocation could be done to balance the load between the lanes more evenly rather than encouraging everyone into lane 1 and leaving lane 2 underused. When 2 lanes can be used to exit for the same destination, it is very common for the majority of traffic to sit in lane 1.
Also can anyone show me some pictures of my these incorrect signs at junctions as I'm not sure how to put them up myself.
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DB617
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Re: Incorrect overhead motorway signage

Post by DB617 »

Of course, the usual problems apply with road design where it has to be designed despite the inevitable idiots. Wherever you have one of these lane splits, you get drivers who leave it too late whether through inattentiveness or bloody mindedness and have to stop the opposite lane and force their way in. While all the drivers who have queued for x minutes try their best to block them (I'm guilty as charged on the A4232). The end result is the entire motorway gets strangled during heavy traffic.
ais523
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Re: Incorrect overhead motorway signage

Post by ais523 »

I discussed the M6/M42 signage with the people responsible for it a while back.

Apparently the issue is that correct signage for the junction's current lane layout is sufficiently complex that some drivers don't understand it and end up making dangerous last-minute manoeuvres and/or running off the road. With the M6 smart motorway scheme, they're planning to change the lane allocation to something that's easier to quickly grasp, for safety reasons.

When you have a lane allocation that's too complex to easily explain, therefore, it may be safer to lie on the signs (suggesting a lane allocation that at least works and is consistent with the markings at the junction, even if it's suboptimal) than to try to explain the full complexities of the junction.
wallmeerkat
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Re: Incorrect overhead motorway signage

Post by wallmeerkat »

Not sure if it's the same, but when I first started driving it, the M8 in Glasgow used to confuse me, and I'd often commit the mortal sin on a GB motorway of sitting in the middle lane, because some lanes are lane drops and others aren't, and the signage isn't always clear on which is coming up.

For example - not a lane drop ahead

Lane drop ahead

I eventually learnt that the lane gains would often become lane drops, and that if there are 4 boxes (for 3 lanes) on the gantry for lightup matrix signs then it means that there is a sliproad to the left ahead, try and read the dashed lines, and that the main 3 lanes aren't dropped.
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wrinkly
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Re: Incorrect overhead motorway signage

Post by wrinkly »

wallmeerkat wrote: Tue Jul 17, 2018 16:18 Not sure if it's the same, but when I first started driving it, the M8 in Glasgow used to confuse me, and I'd often commit the mortal sin on a GB motorway of sitting in the middle lane, because some lanes are lane drops and others aren't, and the signage isn't always clear on which is coming up.
The Glasgow gantries have been a subject of energetic debate on here from time to time because of the way they treat lane drops.
someone
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Re: Incorrect overhead motorway signage

Post by someone »

Admittedly horrible signage aside, but the lane dividers should still show where there is a lane drop.

For an upcoming lane drop the lane is separated by short marks and gaps, the same sort as used for marking the edge of slip roads.

The lanes on the main line still have normal lane dividers: short marks and long gaps or, if warning of a hazard, long marks with short gaps.
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