Smart Motorway - I'm Confused...

[turbojay555]

dr_gn said:

My commute is several miles of M1 (J35 - 31) and back. Today I had to extend the return to J37.

From what I've read on the gov. Website, if a gantry shows a limit (eg 60), then from that gantry onwards it's a 60 limit until another limit, or the national speed limit sign appears on a subsequent gantry.

Today, there was 40 limit and the inner lane closed due to a broken down car. There're were no subsequent gantry signs illuminated for the remainder of the smart motorway several junctions further north. Sometimes there is a n.s.l. Sign after a limit, sometimes not.

Some drivers were doing 70+ In the closed lane Immediately after (and in some cases before) the obstruction was passed, despite no further instruction to negate the lower limit, or indicate the blocked lane was open. Others were doing 40.

Apparently people joining at subsequent junctions didn't have a limit or lane block imposed, but I was still doing 40 for a mile or so before giving up and going with the flow, mainly for safety reasons. Some did likewise, some didn't.

It's totally inconsistent - at first I thought it was due to comissioning the system, but apparently not.

What's correct?

The smart motorway finishes at j35a northbound anyway, and straight after that juction there is a permanent nsl sign on the verge saying end of variable limit, so if you passed that juction on your way up to j37 then you also passed the nsl sign.
Also a lot of the gantries don't have speed cameras so people will get straight back up to speed.

[dr_gn]

turbojay555 said:

dr_gn said:

My commute is several miles of M1 (J35 - 31) and back. Today I had to extend the return to J37.

From what I've read on the gov. Website, if a gantry shows a limit (eg 60), then from that gantry onwards it's a 60 limit until another limit, or the national speed limit sign appears on a subsequent gantry.

Today, there was 40 limit and the inner lane closed due to a broken down car. There're were no subsequent gantry signs illuminated for the remainder of the smart motorway several junctions further north. Sometimes there is a n.s.l. Sign after a limit, sometimes not.

Some drivers were doing 70+ In the closed lane Immediately after (and in some cases before) the obstruction was passed, despite no further instruction to negate the lower limit, or indicate the blocked lane was open. Others were doing 40.

Apparently people joining at subsequent junctions didn't have a limit or lane block imposed, but I was still doing 40 for a mile or so before giving up and going with the flow, mainly for safety reasons. Some did likewise, some didn't.

It's totally inconsistent - at first I thought it was due to comissioning the system, but apparently not.

What's correct?

The smart motorway finishes at j35a northbound anyway, and straight after that juction there is a permanent nsl sign on the verge saying end of variable limit, so if you passed that juction on your way up to j37 then you also passed the nsl sign.
Also a lot of the gantries don't have speed cameras so people will get straight back up to speed.

The permanent nsl sign after J35a isn't the issue, it's perfectly clear what applies after that.

The broken down vehicle was just after J34 (Meadowhall), it's over 4 miles, and many gantries before the end of the smart motorway (after J35a). It was probably 6 or 7 miles between the first 40mph smart sign warning of the obstruction (well before Tinsley viaduct IIRC), and the end of the smart motorway. That's a lot of gantries not displaying anything at all, and a lot of drivers being confused as to what speed they should be driving at. There was also no 'official' re-opening of the closed lane either (I'd expected the next gantry to show nsl on all four lanes after the obstruction).

Another issue is that if you join northbound at J35, the only speed limit on joining is a matrix sign at the exit of the junction roundabout (which I believe is advisory). So in theory, if there's, say, a 40mph limit on the smart motorway, you could, based on what you can see and prevailing traffic conditions, ignore the advisory matrix sign (which may/may not advise 40mph), and join at 70mph and immediately get done by a traffic officer.

Its all very poorly thought out and managed as far as I can see. The two conflicting accounts of where and when speed limits apply in the gov.uk documents linked previously appear to prove this.

[pim]

Maybe the authorities like to confuse Jo public gives them a feeling of superiority.Unless they haven't got a clue what they are doing more likely.

[blueg33]

The slip road at Henley in Arden onto the M40 has a variable limit illuminating sign and about 5 metres on it has a fixed NSL sign, so regardless of the illuminated variable sign, the limit on all but 5 metres of the slip is NSL. The traffic on the M40 when you join it could be limited, but joiners from the slip are not until the first gantry.

Clearly someone didn't plan that right

[Solocle]

blueg33 said:

The slip road at Henley in Arden onto the M40 has a variable limit illuminating sign and about 5 metres on it has a fixed NSL sign, so regardless of the illuminated variable sign, the limit on all but 5 metres of the slip is NSL. The traffic on the M40 when you join it could be limited, but joiners from the slip are not until the first gantry.

Clearly someone didn't plan that right

[Heres Johnny]

There used to be a minimum distance that repeaters had to be placed for a road to be correctly signed, I think they relaxed the obligation in 2016, certainly seem to on local roads, but on a motorway it may still be in force and was/is something like 900m. If you'd travelled that far after a gantry sign and not had a reminder then the road was/is not marked correctly and prosecution would be unsound. That's only about 40s of driving at 50mph.

[Heres Johnny]

Solocle said:

blueg33 said:

The slip road at Henley in Arden onto the M40 has a variable limit illuminating sign and about 5 metres on it has a fixed NSL sign, so regardless of the illuminated variable sign, the limit on all but 5 metres of the slip is NSL. The traffic on the M40 when you join it could be limited, but joiners from the slip are not until the first gantry.

Clearly someone didn't plan that right

That sign can also be used for an advisory which would still be valid even under an NSL. I can see a faint ring which means it could possibly be a variable speed limit but the lights in each corner are associated with warnings.

[Solocle]

Heres Johnny said:

That sign can also be used for an advisory which would still be valid even under an NSL. I can see a faint ring which means it could possibly be a variable speed limit but the lights in each corner are associated with warnings.

From the sound of it, it might well be used for both.

[blueg33]

Solocle said:

Heres Johnny said:

That sign can also be used for an advisory which would still be valid even under an NSL. I can see a faint ring which means it could possibly be a variable speed limit but the lights in each corner are associated with warnings.

From the sound of it, it might well be used for both.

I have seen it lit with the red ring on a couple of occasions. Its my alternate route to the station if the M42 is blocked

[Pica-Pica]

Advanced driving dictates following, is it safe, is it legal; so safety comes first. Also speed limits need repeaters unless they are national speed limit applied, or street lights close together. Note you will notice if you travel on a single carriageway (60 national speed limit) and a junction is lit, the 60 speed limit will be shown (in a small circle) because the 'street lights = 30 does not apply.

There is another location, where you leave the ring road in Liverpool to get on to the M62. As far as I have noticed you turn of from 40mph urban dual carriageway onto another dual carriageway, with no further speed limit signs until you come on to (on this same second dual carriageway) the M62, with the blue motorway signage (but no national speed limit sign). However cars are accelerating up to 70 before this with no signage. To me it is safer to go with the flow, staying in the LH lane, but not becoming an obstruction.