As lighting professionals will be only too well aware, the UK’s street-lighting schemes are undergoing a changeover from older sources such as high-pressure sodium (HPS) and high-intensity discharge (HID) to LED technology. This presentation intends to outline research Lucy has carried out as part of her recent MSc to illustrate how this new street lighting technology affects residents living in suburban environments by exploring factors such as night-time visibility, distribution, preservation of environment, and feelings of safety. The objective is to clarify the perceptions, needs and priorities of urban residents in order to find whether this, coupled with existing measures to reduce light pollution (for example PIR, dimming curfews and so on) can be ultimately harmonious. Such information forms a valid contribution in determining more precise ways of saving energy and globally reducing light pollution levels. Exterior lighting designers, project managers, local authorities, environmental and street lighting engineers would find this really helpful. by Lucy Record, Beam Lighting Design

1. THE EFFECTS OF LED STREETLIGHT TECHNOLOGY ON THE
SUBURBAN RESIDENTIAL ENVIRONMENT
LUCY RECORD
(MSC LIGHT & LIGHTING, UCL)
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
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2. INTRODUCTION
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
General enquiry: The changing vista of the nighttime environment caused by LED streetlighting
Specific focus: Suburban residential environment
Main study: Door to door survey to document the residents perceptions of the upgraded street lighting
Sub study1: Illuminance mapping technique comparing 3 light sources (LED, HID & HPS) in
an authentic setting
Sub study 2: Interview with a street lighting manufacturer
2
Main objectives: can human needs an environmental respect be harmonious?
Further questions: are people adding additional security lighting in response to
the changes?

3. BACKGROUND RESEARCH
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
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The evolution of optical design

4. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019 4
BACKGROUND RESEARCH
Councils across the UK are increasingly under pressure to reduce net CO2 emissions; a major incentive to
seek new means and approaches to lighting up streets at night.1
In February 2014 the UK government reported that the ratio of streetlighting was 1:10 LED to HPS /HID
sources. Last year (2018) LED schemes had only increased by 20%2
In the UK Individual counties autonomously decide on dimming and switch-off policies:
Suffolk switches off their street-lights between midnight and 6am.
Coventry, the lights dim down to 50% after 9pm in the evenings. 1
The overall saving of switching over to LED are estimated to be £200 million with a 10-year payoff period3

5. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019 5
BACKGROUND RESEARCH
In 2016 The UK Government necessitated that LED streetlights have a luminous efficacy of 96 lm/W with a
longevity of 100,000 hours. 4,5
Over 10 years since 2006, the efficiency and the life expectancy doubled. 4,5
Earlier technology typically favoured cooler colour temperature due to the efficiency benefits. 1
By 2025 it is predicted that warm white LEDs will exceed 160lm/W; almost double that of today’s
figures.6

6. BACKGROUND RESEARCH
80% of the global population are exposed to light polluted skies, and two thirds cannot see the Milky
Way where they live.7
Younger generations becoming conditioned to higher levels of light at night due to a lack of reference to
naturally dark skies do not notice the shift. Christopher Kyba: “Shifting Baseline Syndrome”. 8,9
Research about the relationship between LED streetlights and light pollution is in its infancy –
early days still!
Existing research suggests that light-spill is thought to have a greater impact on light pollution
compared to wavelength.10,11,12,13,14,15
Light directed from 90º - 100º angles, - lower upper light output zone (UL)".16
Reflection from roads only accounts for 25% of artificial sky brightness as opposed to
75% from Upward Light.17
ILP GN01:2011
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019

7. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
BACKGROUND RESEARCH
Over 50 years since 1950 to 2000, luminous efficacy of lighting has doubled, and despite this, electricity
consumption has increased by 400% (for lighting alone). 18
Artificial lighting counts for 19% of all electrical consumption worldwide, 15-20% of which accounts for
exterior lighting, which has increased steadily at a rate of 3-6% per year. 18
As lighting becomes cheaper, the likelihood of consumers using it in greater quantities increases. It
is therefore feasible to assume that reduced lighting cost will increase illumination; or that
conversion to energy efficient lighting is unlikely to reduce energy consumption. 8
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019

8. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
BACKGROUND RESEARCH
Shifts in social and psychological concerns, connected primarily with safety are driving forward the need for
good visual acuity in urban areas at night
One study reported that timed switch-offs and dimming curfews are generally unnoticed by
residents, but there is a considerable objection to the concept of darkness or “dim” lighting.19
Whilst the perception of ‘well-lit’ streets at night in residential areas is psychologically connected
with safety and reduced crime/ road accidents, there is a lack of hard evidence to back it up.20,21,22
The St Helens BLISS surveys (2011) attempted to define the characteristics of lighting that induce
a feeling of ‘safety’; it still stands as the most comprehensive qualitative surveys on LED street-
lighting to date.23

9. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019 9
OBSERVATIONAL STUDY: ILLUMINANCE MAPPING TECHNIQUE

10. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019 10
HPS HID LED
HPS HID LED
HPS HID LED
HORIZONTALVERTICALVERTICAL

11. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
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MAIN STUDY: STREET LIGHTING DOOR-TO-DOOR SURVEY - METHODOLOGY

12. MAIN STUDY: STREET LIGHTING DOOR-TO-DOOR SURVEY - METHODOLOGY

13. MAIN STUDY: STREET LIGHTING DOOR-TO-DOOR SURVEY - METHODOLOGY
16-24 25-34 35-44 45-54 55-64 Comment
Age
M F Comment
Sex
Yes No Comment
Registered disabled?
Home Owner
Owned
Outright
Buying on
mortgage
Rent
from
trust
Rent
from
private
landlord
Rent
from
council
Comment
General
Yes No Don't know Comment
Have you noticed any changes in the local
urban environment within the last 1 year?
If so, what?
Street Lighting
Yes No Don't know Comment
Have you noticed any change to the street
lighting lately?
1 2 3 4 5 Comment
Pleasant Unpleasant
What do you think of the colour of the new lighting?
Brighter Darker
Is it brighter or darker in comparison to
previous lighting?
Yes No Don't know Comment
Have you noticed any unwanted light spill in
your bedroom at night?
Is this a problem? If so, why?
Coverage
Yes No Comment
Does the street look evenly lit?
Is it important that the street lighting lights up
the front garden?
Is it important that the street lighting lights up
the front façade of the house/flats?
Do you have any existing local lighting on front
of side of house, e.g. Security, aesthetics?
Have you added any extra lighting on the front
or side of your house within the past year?
Any Plans to?
Environment
Yes No Comment
Do you think it is important to have some areas
of darkness in the nightime urban
environment?
Do you feel that it is important to have the
street lights on at full power all night?
Do you feel that the new LED lighting is better
for the environment?
Is light pollution an issue in this area?
Don't know
Demographics
Don't know
DEMOGRAPHICS:
AGE
SEX
HOME OWNERSHIP
GENERAL:
HAVE YOU NOTICED ANY CHANGES?
NEW STREET LIGHTING:
COLOUR TEMPERATURE
BRIGHTNESS
LIGHT SPILL
DISTRIBUTION
EXPECTATIONS:
WHAT SHOULD BE LIT?
ENVIRONMENTAL CONCERNS
DIMMING CURFEWS
SECURITY LIGHTING:
EXISTING?
PLANS TO ADD?

14. MAIN STUDY: STREET LIGHTING SURVEY - RESULTS
Two busy roads:
Didn’t generally notice any changes to the street lighting
Commented that the light distribution of LEDs was “uniform”
Felt that street lighting should not encroach into their front gardens or house facades
Were slightly more in favour of areas of darkness in the urban environment
Quiet road:
More astute to general changes in their surroundings, and therefore the street lighting
Were in favour of street lights lighting up to their front door, but not spilling onto the house façade.
Had a greater concern about light pollution in their area yet were more in favour of full power street-
lighting throughout the night
Higher concern over safety
Demographical comparisons:
The two busy roads had predominantly younger male participants who were renting tenants
The quiet road had more older female home owner participants
Majority of all participants:
In favour of dimming curfews
Concern over light pollution levels in their local environment
Lucy Record – ILP Professional Lighting Summit – Newcastle 2019

15. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
An unlikely outcome of the study was that urban residents, being already exposed to high levels
of light pollution, were open to the idea of retaining areas of darkness and implementing
dimming curfews.
15
MAIN STUDY: STREET LIGHTING SURVEY – DISCUSSION & CONCLUSION
The study could reinforce discussion about dimming/switch-off curfews, despite the bad press
against it.24
Questions raised about what qualities of street-lighting induce a feeling of ‘safety’? 25
Early signs of additional security lighting as a response to the new street lighting:
7 people out of the 43 surveyed had installed extra lights in response to the changed scheme, which is 16%. Put this
figure into the larger picture of households in the UK (26.7 million) and the potential is 4.27 million households
adding additional lighting.
Younger people are less aware of rising levels of light pollution due to a gradual conditioning.

16. Lucy Record – ILP Professional Lighting Summit – Newcastle 2019
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“Should we cater for a very small number of people walking around at 2am?
Probably not. You can't accommodate such a small percentage of people who
might be fearful.”
Resident, Archway Road

17. THANK YOU
17

18. 1. Parry, N. (2016). Interview 7/6/16
2. Anon, (2019). Annual Report. [online] Available at: https://www.localgov.co.uk/LED-street-lights-could-save-councils-200m-a-year-campaigners-say/44106
3. Anon, (2014). Annual Report. [online] Available at: http://green investment banking 2014 [Accessed 12 Feb. 2016].
4. Energy.gov. (2016). LED Basics | Department of Energy. [online] Available at: http://www.energy.gov/eere/ssl/led-basics [Accessed 13 Aug. 2016].
5. Herefordshire.gov.uk. (2016). LED street lights - Herefordshire Council. [online] Available at: https://www.herefordshire.gov.uk/environmental-protection/conservation-and-
sustainability/led-street-lights [Accessed 13 Aug. 2016].
6. Anon, (2008). [online] Available at: http://cool.conservation-us.org/byorg/us-doe/color_rendering_index.pdf [Accessed 14 Aug. 2016].
7. Falchi, F., Cinzano, P., Duriscoe, D., Kyba, C., Elvidge, C., Baugh, K., Portnov, B., Rybnikova, N. and Furgoni, R. (2016). The new world atlas of artificial night sky brightness.
Science Advances, 2(6), pp.e1600377-e1600377.
8. Kyba, C., Hänel, A. and Hölker, F. (2014). Redefining efficiency for outdoor lighting. Energy & Environmental Science, 7(6), p.1806.
9. Pauly, D. (1995). Anecdotes and the shifting baseline syndrome of fisheries. Trends in Ecology & Evolution, 10(10), p.430.
10. Red is the new black: how the colour of urban skyglow varies with cloud cover
11. Kyba, T Ruhtz, J Fischer… - Monthly Notices of the …, 2012 - mnras.oxfordjournals.org
12. Kyba, C., Ruhtz, T., Fischer, J. and Hölker, F. (2011). Cloud Coverage Acts as an Amplifier for Ecological Light Pollution in Urban Ecosystems. PLoS ONE, 6(3), p.e17307.
13. Luginbuhl, C. (2001). Why Astronomy Needs Low-Pressure Sodium Lighting. Symposium - International Astronomical Union, 196, pp.81-86.
14. Anon, (2016). [online] Available at: http://Night Sky to Turn Bluer? Energy-efficient streetlights may change color of light pollution. By Dave Mosher, for National Geographic
News. Published August 2014 [Accessed 12 Aug. 2016].
15. Rea, M. and Bierman, A. (2014). Spectral considerations for outdoor lighting: Consequences for sky glow. Lighting Research and Technology, 47(8), pp.920-930.
16. ILP: Guidance Notes for the Reduction of Obtrusive Light GN01:2011
17. Falchi, F., Cinzano, P., Elvidge, C.D., Keith, D.M. and Haim, A., 2011. Limiting the impact of light pollution on human health, environment and stellar visibility. Journal of
environmental management, 92(10), pp.2714-2722.
18. Hölker, F., Moss, T., Griefahn, B., Kloas, W., Voigt, C.C., Henckel, D., Hänel, A., Kappeler, P.M., Völker, S., Schwope, A. and Franke, S., 2010. The dark side of light: a
transdisciplinary research agenda for light pollution policy.
19. Green, J., Perkins, C., Steinbach, R. and Edwards, P., 2015. Reduced street lighting at night and health: a rapid appraisal of public views in England and Wales. Health &
place, 34, pp.171-180.
20. Marchant, P., 2010. What is the contribution of street lighting to keeping us safe? An investigation into a policy. Radical Statistics, 102, pp.32-42.
21. Marchant, P.R., 2004. A demonstration that the claim that brighter lighting reduces crime is unfounded. British Journal of Criminology, 44(3), pp.441-447.
22. Steinbach, R., Perkins, C., Tompson, L., Johnson, S., Armstrong, B., Green, J., Grundy, C., Wilkinson, P. and Edwards, P. (2015). The effect of reduced street lighting on road
casualties and crime in England and Wales: controlled interrupted time series analysis. J Epidemiol
23. St Helens Council, (2011). BLISS Surveys. St Helens: IPSOS MORI.
24. Green, J., Perkins, C., Steinbach, R. and Edwards, P., 2015. Reduced street lighting at night and health: a rapid appraisal of public views in England and Wales. Health &
place, 34, pp.171-180.
25. Sutton, R. M. and S. Farrall (2005). "Gender, Socially Desirable Responding and the Fear of Crime." British Journal of Criminology 45: 212-224.
References

19. Many thanks to Jess and Jo at the ILP for the generous opportunity to attend the ILP conference, Newcastle and
present my work.
I would like to express sincere gratitude to the tutors of MSc Light and Lighting at The Bartlett, University College London,
who supported me throughout the process of writing this paper, namely Dr Jemima Unwin and Dr Peter Raynham.
I would also like to sincerely thank Nigel Parry (OrangeTek) for lending his time and expertise in the interview which forms
a large portion of the supporting research.
Finally, I would like to give great credit to both my parents, Liz and John for their financial and emotional support
throughout Masters Degree.
Acknowledgements