Carriageway lighting on (smart) motorways

[ManomayLR]

So recently, I've discovered that a lot of sections of motorway that were once lit have had their carriageway lighting removed since. For example, the M25 between J23 and J24 was originally lit with central reservation lighting but this was removed with the introduction of all-lane running.
Also, the M1 just after J10 originally had carriageway lighting, which was also removed with the smart motorway.

Why is this happening? Surely it's a safety risk given there's no hard shoulder?

[Chris5156]

The short answer is that it’s cheaper not to have lighting. It tends to be removed rather than replaced on motorways now, once equipment reaches the end of its life.

There was some research a few years ago that showed motorway lighting did not deliver the benefits in accident and casualty reduction that had been assumed when it was installed on long stretches of rural motorway during the 70s and 80s. It’s been used as one of the justifications for getting rid of a lot of lighting.

I have a vague feeling that there was also some claim that the technology on Smart Motorways would compensate for any safety disbenefit in removing lighting.

[jervi]

Just a bit of speculation, when a motorway is converted into ALR, some of the central reservation has to be used as the HS isn't quite wide enough. As a result of that the room for the vehicle restraint barrier is reduced, so instead of using two armco barriers with room for lighting columns in between, they just opt for a single concrete barrier. And installing lighting columns on concrete barriers is possible, but maybe just not a suitable or viable option.
I'm guessing the main reason for installing lighting on motorways in the first place was so drivers were able to see broken down cars / accidents further ahead, so smart motorway technology should do that now instead, so the main need for lighting has been reduced.
However, if you are broken down in the middle of the night, it would be much nicer and safer if there was lighting

[c2R]

The main reasons it was originally installed was:
* large pile ups caused by fog/smog
* car headlights less powerful than today
* lit motorways reduce driver fatigue, particularly in heavy traffic

I think Chris is right with the justifications for reasons it was removed; however, I think it's a mistake, partiularly where there is no hard shoulder and on motorways with high traffic volumes.

[Micro The Maniac]

In addition to all the above points, there is also a level of Green Wash about it.

We've seen this with urban/residential street-lighting being switched off (typically between midnight and 5am) as an environmental measure - both as a saving in electricity and lowering light "pollution" - as well as savings in maintenance.

The amount of electricity required to light miles and miles of motorway must be considerable....

[orudge]

The amount of electricity required to light miles and miles of motorway must be considerable....

Although nowadays with LED lighting I’d expect power usage to be considerably lower (though not non-existent of course).

[c2R]

However, power generated at night is really cheap - it's not possible to shut down large nuclear /coal / oil power stations overnight, and as most industry isn't operating, and people are in bed, demand is low while there's still a lot of supply. I'm therefore sceptical that the environmental benefits are a particularly good justification...!

[Gareth]

I think the environmental benefits mostly pertain to light pollution.

Of course, a well designed modern lighting scheme can result in very little upward light pollution.

That leaves you with installation and maintenance costs, which could perhaps be uncharitably be seen as penny pinching.

[someone]

* car headlights less powerful than today

Indeed, as always the assumption made is that everyone only drives a car (or van, lorry, etc.)

For various reasons I only ride a motorcycle (and have never had car driving lessons) but the LED headlamp on my 2016 bike is almost useless. The first time I rode it in the dark was coming home to London from visiting my sister in Essex, so used the M11.

It was the most terrifying experience I have had on a bike. The only time I could see anything of the road ahead was when I had a car behind me. There is also a section either before or after Bishop's Stortford where there are no road studs, so when I entered that I could not even see where the lanes were. I basically had to sit behind a lorry and follow that, and hope there was nothing on the road.

I am using a modern vehicle legally allowed to use motorways, and which has passed all the legal requirements to be used on British roads, including at night. And somewhere that system has failed, I am sure in part because the sort of people making these decisions do not consider all types of road users.

Either a bike headlamp should meet the same output as one car headlamp, or street lighting requirement should be consider the most vulnerable road users and not just the largest category of them.

And the same can be said of urban street lighting, because the newer ones the council installed where I live are equally as useless. Not only are they not particularly bright unless you are directly by a post, they alternate sides of the road so leave large patches of darkness as the shadow of parked cars block the light. Walking down residential streets is now a somewhat scary experience.

Anyway, I have tried adding some extra spotlights on my bike but they have not helped, they are very bright but the light is scattered too widely. They can light up a room, but on an open road most of is lost in the air.

My dad has been very ill the past few months and so I have spent a lot of time travelling to Lincolnshire. This has meant planning journeys so that the sun does not set until I reach somewhere lit by streetlights. So as night gets significantly earlier I am still looking to experiment with other spotlights, but unless and until I can find something suitable I just cannot travel in the dark.

[KeithW]

However, power generated at night is really cheap - it's not possible to shut down large nuclear /coal / oil power stations overnight, and as most industry isn't operating, and people are in bed, demand is low while there's still a lot of supply. I'm therefore sceptical that the environmental benefits are a particularly good justification...!

There are no large oil plants left at all, coal is now a very low percentage as at this moment is wind. Thus is the breakdown from the usage last night was.

Total demand at around midnight 30 GW

UK Supply
Combined Cycle Gas Turbine 14 GW
Coal 1.2 GW
Nuclear 5.6 GW
Wind 5 GW
Hydro 1.2 GW
Solar 0
Biomass 1 GW

The surplus was exported via the Interconnects

At this moment (10.54 AM) Demand is approx 38 GW

UK Supply
Combined Cycle Gas Turbine 22 GW
Coal 2.2 GW
Nuclear 5.6 GW
Wind 2 GW
Hydro 1.2 GW
Solar 2
Biomass 1 GW

Total UK Generated 36 GW
Imports via Interconnectors 2 GW

We have no realistic control over wind or solar generation levels so in winter the base load has to be carried by Gas Turbines, Nuclear, Coal, Hydro and Biomass (old coal stations burning imported wood pellets)

Load balancing therefore HAS to be done mainly by turning coal and gas powered stations off which is expensive as CCGT generation is the cheapest form of generation and produces the lowest emissions of CO2 and Particulates of all the thermal methods while the coal boilers have to be kept going at low load levels so as to be available to meet a rise in demand.

Pumped storage is now used mainly as a last resort. If the grid completelycrashed it would provide the capacity for a start from a scratch.

As has been said concerns about light pollution are the main reason for reduced lighting. In towns this is one of the drivers behind the use of directional LED lamps.

[jusme]

Of course "Smart" motorways use CCTV for monitoring. CCTV requires light, so there's IR lighting in place, instead of visible lighting that would help drivers see upcoming obstructions better...

[thatapanydude]

To be honest this is a shambles. Street lighting improves safety as for example on an ALR motorway, if a car was stationary on the nearside lane in the dark having lighting would make it easier to identify.
In my opinion it should be brought back across the whole M25, M1 and M6 (upto the M55 turnoff) and hopefully they can keep the lighting on the M4 as well.

[Chris5156]

Just a bit of speculation, when a motorway is converted into ALR, some of the central reservation has to be used as the HS isn't quite wide enough. As a result of that the room for the vehicle restraint barrier is reduced, so instead of using two armco barriers with room for lighting columns in between, they just opt for a single concrete barrier. And installing lighting columns on concrete barriers is possible, but maybe just not a suitable or viable option.

This is why, where lighting is required on Smart Motorways or other roads refurbished with a single continuous concrete barrier, the lights are installed on the verges instead. Verge lighting costs a bit more because it requires twice as many columns and two parallel runs of power supply cabling, which is why central reservation lighting was the norm for many years, but it has the advantage that the lights are more easily reached for maintenance and require fewer lane closures - that is supposedly a quantifiable benefit on a very busy motorway.

The above might also have contributed to the justification for removing lighting from Smart Motorways. It would have to be reinstalled from scratch in the verges, and that would be a very high cost to add to all the other works. It would not be as simple as just keeping the existing lights.

[Debaser]

Lighting has to be justified in terms of cost versus the benefits from accident savings. The old value used was 30% of darkness collisions were saved by street lighting. The current value used in assessments is a 10% saving. It is therefore much more difficult to get the cost benefit calculation to be favourable.

BTW, street lighting is not a universal benefit. Whilst it does reduce collisions involving older drivers it actually has the opposite effect for younger drivers, increasing the number of collisions they are involved in. Something to do with increased confidence IIRC.

[KeithW]

The main reasons it was originally installed was:
* large pile ups caused by fog/smog
* car headlights less powerful than today
* lit motorways reduce driver fatigue, particularly in heavy traffic

I think Chris is right with the justifications for reasons it was removed; however, I think it's a mistake, partiularly where there is no hard shoulder and on motorways with high traffic volumes.

There were claims back in the 1970's that huge improvements in safety could be made by increasing lighting on motorways. When lights were installed the results showed only marginal improvements which were hard to differentiate from the falling fatality rates that were occurring anyway. The problem with fog especially on a motorway or high speed dual carriageway is that you can be in clear conditions one minute and then come round a corner or over the top of a hill and find yourself unexpectedly in a bank of dense fog. The effectiveness of old fashioned fog warning lights was not great as they were often not accurate. Many were activated from police patrol vehicles and all too often not cancelled. In such situations the driver was caught between a rock and a hard place. My natural response to slow down was tempered by the knowledge that drivers behind me likely would not. There was one drive down the M1 at this time of year when I passed a column of cars who were all doing about 60. I ran into a very dense bank of fog and slowed to 40 and turned on my after market rear fog lights. I would have preferred 30, a few minutes later that column of closely spaced cars came past me - still doing 60.

With Smart roads using CCTV and VMS signs you can have much better surveillance which can give more detailed warnings such as "Dense Fog after Junction 12". You can also have a variable speed limit to reduce speed on the road.

I never found street lights particularly useful when driving in fog. Actually I think the mandatory fitting of elevated brake lights and rear fog warning lights was much more useful. That said I think they are needed in urban locations and at busy junctions in rural locations. Take the example on the roundabout at the junction of the A1198 and A603/B1042. It used to have a terrible safety record but the lighting on the approaches really helped.

https://www.google.co.uk/maps/@52.12365 ... authuser=0

[DB617]

If (and I mean *if*) the decision to remove lighting on ALR had anything to do with a risk assessment claiming that a controlled motorway would be safer at night despite lack of a hard shoulder because of monitoring, I think that's yet another example of where HE seemed to assume their system was infallible. It's almost as if either nobody ever anticipated having less than 100% constant controller eyes-on the entire network, or they was acting like stopped vehicle detection would be in place on day 1, removing the need for eyes, for drivers and controllers. Alas, I expect everyone above is correct and it was mostly uneconomical to replace the lighting. SVD and permanent lighting (even if at a low brightness) should be a requirement outcome of the investigation into ALR deaths.

Sadly I have bigger, more local things to worry about currently as large sections of the lighting on the A4050 has been out of commission for months (very belated arrival of contractors seems to have occurred this Friday) and the new A4226 link road has been designed for NSL but with three totally unlit ghost island junctions. No illumination, no monitoring, just some of the worst drivers in Wales combined with an extremely high risk road design. People are predicting carnage and for once I don't think they're wrong.

[B4444]

There's maybe this reason for their removal: rusted away

[Brenley Corner]

I noticed on a trip under & over the Thames this week that the street lighting on the southern approach to the Dartford Tunnel has been removed between J1a & J1b - and that large sections of the lighting on the M25 between the M11 and the A12 appears to have been turned off (seems to be too long and too 'co-ordinated' to be a failure).

Tony

[ManomayLR]

There are still signs on the M25 warning of lighting switched off from Midnight to 5AM during the failed trial of part night lighting. I don’t understand - they’re not only removing lighting but also where there is lighting saying that not having it is unsafe. There should be verge lighting on ALR for people who are broken down in a live lane.

[ManomayLR]

To be quite honest I do miss the bright orange glow of the old style lights on the M25.