Lighting one side of a dual carriageway
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Lighting one side of a dual carriageway
Recently I've come across several locations where the full width of a dual carriageway is lit by one row of very powerful streetlights at one side of the road - nothing in the central reserve, nothing on the opposite verge. I guess this saves installation and maintenance costs, and possibly power consumption too.
There's two on the A1 that I passed last night - one between Tempsford and Sandy (too recent to appear on Streetview) and another here near Hendon. These are managed by the HA and TfL respectively, so it's clearly not one highway authority's trick. The Hendon one is particularly noteworthy as the lights also supposedly light the parallel service roads - a total of four carriageways - but don't seem to do a very good job of lighting much beyond the northbound carriageway in reality.
Is this a new recession-friendly technique for lighting dual carriageways? Are there more examples?
There's two on the A1 that I passed last night - one between Tempsford and Sandy (too recent to appear on Streetview) and another here near Hendon. These are managed by the HA and TfL respectively, so it's clearly not one highway authority's trick. The Hendon one is particularly noteworthy as the lights also supposedly light the parallel service roads - a total of four carriageways - but don't seem to do a very good job of lighting much beyond the northbound carriageway in reality.
Is this a new recession-friendly technique for lighting dual carriageways? Are there more examples?
Chris
Roads.org.uk
Roads.org.uk
- Johnathan404
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Re: Lighting one side of a dual carriageway
It wouldn't just save on the obvious maintenance cost, but it also means you can also access them with only a single lane closure (if that, depending on how much verge is available and whether you needed to get to the lamp), as opposed to two outside lane closures for central reservation lighting.
Have never seen this design though.
Have never seen this design though.
I have websites about: motorway services | Fareham
Re: Lighting one side of a dual carriageway
I've seen it done in France but not the UK, suspect as Haydn says light spill is actually not that great.
Bryn
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Terminally cynical, unimpressed, and nearly Middle Age already.
She said life was like a motorway; dull, grey, and long.
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Re: Lighting one side of a dual carriageway
The A34 just south of the M40 junction heading towards Oxford has a short stretch of 'one sided' lighting on mainline D2 A34. I think it's SOX lighting if memory serves.....
Re: Lighting one side of a dual carriageway
Certainly is! If you follow the road south on the GSV link I posted, you'll see the lights run on both sides of the road once you approach the next set of lights, and where there are lights on both sides the columns and outreach arms are half the size. Those are some huge streetlights on the one-sided section.Haydn1971 wrote:That's a long throw to reach the opposite kerb !
But it's a big job to ask no matter how tall the column and how bright the lamp, and I really don't think it does the job for a four-carriageway road!
Chris
Roads.org.uk
Roads.org.uk
Re: Lighting one side of a dual carriageway
Not really with proper choice of lantern and reflector design. You can get surprisingly defined light spread.Haydn1971 wrote:That's a long throw to reach the opposite kerb !
Bit like these babies in Grimsby. There's another bridge further east lit the same.
Re: Lighting one side of a dual carriageway
I'll reserve further comment until I've seen them in the dark
Re: Lighting one side of a dual carriageway
To be fair it's not bad on the ground... lighting levels are exactly what you would expect.
It just looks different because the light source isn't nearby.
Given the classification of the road and knowing the lighting engineers there, I have more than every confidence that lighting levels are to standard.
Of course, if I can find the time and inclination, I'll get pics while I'm home for Xmas.
It just looks different because the light source isn't nearby.
Given the classification of the road and knowing the lighting engineers there, I have more than every confidence that lighting levels are to standard.
Of course, if I can find the time and inclination, I'll get pics while I'm home for Xmas.
- sotonsteve
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Re: Lighting one side of a dual carriageway
At M25 J5, heading anticlockwise, as the slip road for the M25 peels away from the M26 the columns in the verge of the M25 slip road also illuminate the eastbound carriageway of the M26.
- Patrick Harper
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Re: Lighting one side of a dual carriageway
I'm sure a small section of the M6 in Cumbria had one-sided lighting, but that was 2 years ago now. I believe they are GEC SON vintage, and probably for maintenance purposes.
- poshbakerloo
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Re: Lighting one side of a dual carriageway
I suspect two reasons - one is that lights on the verge are easier to reach and maintain than lights in the central reserve (in particular, the example I posted of the A1 at Hendon has an extremely narrow central reservation and you would have to close a lane to reach the lights if they were there). The other is that both examples I posted had lights down the side verges before, and when the new replacements were put up, running a new power line down the central reservation would have been a significant cost when the object seems to have been saving money. Running the single line of lights down one side would have re-used an existing cable run.poshbakerloo wrote:Why didn't they just put them down the centre.
Chris
Roads.org.uk
Roads.org.uk
Re: Lighting one side of a dual carriageway
*Bump*
I've found another example of this, from a different authority again. The Skanska lighting PFI operating in Croydon has put new lights up the A212 Gravel Hill, a dual carriageway on the outskirts of Croydon, which run only on the right-hand side of this view. They're tall with a short outreach arm and are obviously intended to light the whole road.
The example in my original post, the A1 at Tempsford, is now on Streetview - you can see there's just one line of lights there too.
I've found another example of this, from a different authority again. The Skanska lighting PFI operating in Croydon has put new lights up the A212 Gravel Hill, a dual carriageway on the outskirts of Croydon, which run only on the right-hand side of this view. They're tall with a short outreach arm and are obviously intended to light the whole road.
The example in my original post, the A1 at Tempsford, is now on Streetview - you can see there's just one line of lights there too.
Chris
Roads.org.uk
Roads.org.uk
Re: Lighting one side of a dual carriageway
The A212 columns are Stewart and Lloyds from the 1950s; shame they're gone. Similar to what Birmingham used to use.
Bryn
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
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
Re: Lighting one side of a dual carriageway
Croydon was bristling with them until a couple of years ago. The PFI is getting through them like nobody's business now.Bryn666 wrote:The A212 columns are Stewart and Lloyds from the 1950s; shame they're gone. Similar to what Birmingham used to use.
Chris
Roads.org.uk
Roads.org.uk
- Beardy5632
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Re: Lighting one side of a dual carriageway
The A472 in Pontypool is a good example.
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- Johnathan404
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Re: Lighting one side of a dual carriageway
Except on the A32, I have seen it.I wrote:Have never seen this design though.
I have websites about: motorway services | Fareham
Re: Lighting one side of a dual carriageway
Passing through the A1 at Elkesley last week and the northbound carriageway through the new junction is lit from single columns in the central reservation, whilst the southbound is lit from columns on the verge, which I found an odd arrangement.
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- Johnathan404
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Re: Lighting one side of a dual carriageway
I would suggest that's because of the bends. The outside of a bend is longer than the inside of a bend so more lighting is required on that side, whereas on a straight road you can light from any side.
Although last time I used that part of the A1 it seemed pretty messy anyway, so messy lighting would fit in.
Although last time I used that part of the A1 it seemed pretty messy anyway, so messy lighting would fit in.
I have websites about: motorway services | Fareham