Switching off our street lights

Nigel Parry of the Institution of Lighting Professionals argues the case for good street lighting, and explains what effect switching them off could have in terms of safety

The budget cuts that the coalition government has introduced, combined with its Carbon Reduction Commitment and associated tax on carbon-based energy consumption, have re-ignited the zeal of accountants and local authority managers to make easy savings by switching off our street lights. Although the UK Government is keen to make financial savings it is very conscious of the potential of switching lights off and at the start of September last year Louise Ellman MP, a member of the Commons Transport Select Committee, was quoted as saying: “I am extremely concerned that financial pressures are leading to steps which can jeopardise people’s lives and increase the number of injuries.”

These money-saving initiatives take no account of the known benefits that good lighting brings to the community. These include:
1. Reduction in street crime and the fear of crime – helps the authority meet its requirements under the Crime and Disorder Act
2. Reduction in the number and severity of night-time road accidents, by up to 30 per cent
3. Helps emergency services carry out their roles after dark – providing sufficient illumination to work safely and effectively
4. Increases evening activity through:
a. Confident use of public transport
b. Freedom to walk the streets after dark safely
c. Access to evening work, educational and leisure activities.
Good public lighting is essential in allowing life to continue after dark and allows people to go out without the fear of being attacked or run over due to lack of visibility.

Implications of switch-off
Various highway authorities have started switching off street lights to save money. Buckinghamshire, for example, has blacked out areas and has seen a number of accidents in these non lit places. The coroner investigating a fatality in one of these areas has directly linked the lack of lighting with the accident “as the driver had no chance to see the lady crossing the road without any street lights operating”.

Some communities have rebelled against their local authorities and in 2008 a resident of Llangynop, a village in South Wales, paid £295 to have his village lit at night for the winter after Powys Council turned off the street lights to save money. This worked out to around 15 p per lamp per night.

Prisoners in our homes
Lack of lighting on our streets at night can have dramatic effect on society, particularly on age groups at either end of the spectrum. Not just the elderly but the young as well can feel like prisoners in their own homes, too afraid to go out after dark.

A recent report by children’s charity PLAN UK highlighted that 91 per cent of 13-18 year old girls said better street lighting would make a big difference to feeling safe on the streets. The charity’s CEO Marie Staunton said that issues such as poor street lighting needed to be tackled (and not switched off).

An extract from the Police Road Death Investigation Manual clearly identifies the responsibility of the local authority: “When a collision has occurred and highway involvement is alleged then the highway authority should be able to show that it took reasonable measures to ensure that the safety of road user was not compromised.”

Associated issues for switching off include:
• Speed limit signs will require new signage
• Will CCTV cameras work at night with no lighting?
• Labelling of area to confirm the lights aren’t supposed to work
• Photo cell change to part night costs £21
• Installation of road studs (cats eyes) approx 111/km @ £20 each =£2,220 (motorways and high speed roads – Traffic Signs Manual)
• Effect on energy rates – reducing night time low rate usage can impact on authorities’ overall energy tariff by increasing percentage of daytime use. Energy suppliers are reviewing use of variable rates and as the energy saved during midnight until 6am is at a lower tariff cost savings won’t be fully realised.

Furthermore, we have to take into account accident costs. If we take the Highways Agency’s example of switching off from midnight to 5.30am on the motorway and major roads, we can see that the energy saving will be around 50 per cent. Dimming the same lights to 50 per cent power for the same time, thereby reducing the light levels but importantly keeping the uniformity of the street lighting, which is a key factor to reducing glare, would reduce the energy cost by 25 per cent but with no risk to road users.

A recent survey carried out by the Institution of Lighting Professionals (ILP) indicates that the average UK street lamp is 70 watt with an annual energy bill of just £30.
With the cost of accidents being roughly 10 to 1 from fatal to slight (see table)

Therefore one fatality could pay for an entire county’s street lights to be kept on for a year.

Additional costs for permanent switch off include the removal of electrical supply at £400 per lamp, and the removal of equipment at £85 per lamp.

Relighting scheme
Good lighting provides many benefits as mentioned at the start of this article, and those benefits may be most noticeable during the peak times in winter. However, good lighting is just as important to the police and other emergency services every night of the year when responding to emergencies or simply deterring criminal activity.

Some recent evidence of this can be found in a recently completed private finance initiative (PFI) relighting scheme in Wakefield, which has provided some interesting results. The borough has substantially relit its highway network during the last five years and the new lighting:
• helped reduce vehicle collision and damage by 50 per cent – 143 (2004) to 69 (2008)
• helped reduce vehicle crime by 62 per cent between 2004-2008
• helped reduce night time accidents, with overall accidents down by 31 per cent, and night time fatalities down from 9 in 2004 to 0 in 2009.

Save with lights on
The UK has always been at the forefront when it comes to efficient lighting sources and we are still leaders of lighting initiatives.

All UK roads are lit to a British Standard, which sets differing light levels for different road types. Interpretation of the guidance has led to some areas being lit to higher levels than are needed. Therefore a review carried out by the local authority lighting professional of the appropriate lighting standards as part of a lighting policy is recommended to see if light levels could be lower.

It has long been recognised that a quality measure of a lighting scheme is its uniformity level, and a road with good uniformity could be lit to a lower level and still appear as bright to aid visibility. Switching off every other lamp or one in three street lights wrecks the uniformity and provides the comparatively dark shadows that can cause further problems.

Another key design component is control of glare, and the last 20 or so years have seen the introduction of street lamps that have excellent control of the light, only directing it where required with minimal glare. This has resulted in a dramatic drop in the orange glows over our urban conurbations and improvement to the night sky.

Technology
The UK was the first country in the world to recognise the implications of mesopic vision and the benefits of white light. In 2003 we changed our national codes to allow a drop of a whole lighting class if white lights were used on residential roads. Further research has concluded this could be applied to traffic routes and the next BS update may reflect this option.

Central management systems are now available to allow control of every lighting point in an authority. This is a viable cost option that will not only save money through dimming but also ensure that the lighting system is always working at its most efficient. It could provide information so that we never see a light out on the street because they are replaced before they fail.

Light Emitting Diodes (LEDs), street lights capable of actually lighting the streets to the correct level, have been available for a while now and recently we have seen large versions capable of lighting our main traffic routes come to market. As with any new technology the items are expensive but as development continues, we will see the light output rise year upon year and the prices of the core LEDs themselves will start to drop significantly. The USA Department of Energy forecasts that LED chips may halve by 2015 and could drop to 1/25th of current prices by 2020.

What we need is essentially the right light in the right place at the right time. This can be achieved by employing a competent lighting professional so an authority can look to achieve the optimum solution for their road network and customers. Solutions such as the use of energy efficient equipment, the correct application of lighting levels and dimming solutions can assist with this. However, this kind of work must be undertaken in line with the appropriate standards and for example the switching off of every other light is not a viable option.

The ILP is not saying don’t switch lights off but this must be seen as a last resort, and if followed other road safety measures such as improved signing must be employed.

For more information:
Web: www.theilp.org.uk