Through the prism of sustainability and energy saving, this session will focus on the key attributes of "Variable lighting levels for highways & public realm areas". Previous and current guidelines of the dimming strategies will be presented and discussed through the award-winner case study "Variable Lighting Levels for Highways – A different approach". Having won the “Young Lighter of the Year 2016” and the “Best written paper” awards by the Society of Light and Lighting (CIBSE SLL), this paper presents an approach towards energy savings in the context of highways and public realm lighting. The session aims to present the current state-of-the-art through the perspective of a young professional, discussing also several key matters and concerns one can encounter during the early career stages. Talk by Sofia Tolia MSc MEng, Ringway Jacobs

1. Variable Lighting Levels for Highways
A Different Approach
ILP Summit
14.06.2017 Institution of Lighting Professionals
Sofia Tolia MEng, MSc
Lighting Engineer, Ringway Jacobs
YLP Vice Chairman

2. ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
• August 2013 Dissertation for completion of MSc Light and Lighting at
UCL
• August 2016 Revised for submission of the SLL competition Young
Lighter of the Year.
• May 2017 Revised with additions for ILP Summit

3. Introduction
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
Variable Lighting Levels for Highways
A Different Approach
Sofia Tolia MEng, MSc
Lighting Engineer, Ringway Jacobs
YLP Vice Chairman

4. Introduction
19%
Global Electricity Consumption
Lighting
42%
Global Electricity
Consumption from Lighting
Indoor
Outdoor
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

5. Introduction
Sofia Tolia
Ringway Jacobs
ILP Summit
14.06.2017

6. Introduction (cont’d)
HOW??
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

7. Introduction (cont’d)
Energy Efficient
Designs with energy efficient light sources LEDs
Reduce light levels with reduction of the
traffic flow
Control Systems
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

8. Current State-of-the -art
Control Strategies
Photocells –
ON through night
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

9. Current State-of-the-art (cont’d)
Control Strategies
Luminaires turned off
Manually/ with timer
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

10. Current State-of-the-art (cont’d)
Control Strategies
Every Second Luminaire switched off
With timer
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

11. Current State-of-the-art (cont’d)
Control Strategies
Dimming
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

12. Current State-of-the-art (cont’d)
Dimming
Passive
Fixed switching regimes via
central control system (CMS)
Dynamic
Adjust dimming values via control
system linked to active traffic
monitoring equipment
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

13. Current State-of-the-art (cont’d)
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
Average Daily Traffic Flow (ADT)
Average Hourly Traffic Flow

14. Previous Standards
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
TR 27
Code of Practice for Variable Lighting Levels for highways
Assumption: Pick traffic flow 10% of ADT for
rural areas and 12% of ADT for urban areas
• Maximum Hourly Value (Peak)= Daily Sum

15. A Novel Calculation Approach
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
𝑇𝑟𝑎𝑛𝑠𝑖𝑡𝑖𝑜𝑛 𝐿𝑒𝑣𝑒𝑙 =
𝐵𝑆 𝑡ℎ𝑟𝑒𝑠ℎ𝑜𝑙𝑑 ×𝑀𝑎𝑥 𝐻𝑜𝑢𝑟𝑙𝑦 𝐹𝑙𝑜𝑤
𝑀𝑎𝑥 𝐷𝑎𝑖𝑙𝑦 𝐹𝑙𝑜𝑤
Max Daily Flow= ADT (Sum of the hourly values)

16. Current Standards
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
PLG 08
Guidance on the application of adaptive lighting
within the public realm

17. Current Standards (cont’d)
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

18. Case Study: Piraeus Port
Port of Piraeus, Greece
12 measuring positions
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

19. Case Study: Piraeus Port (cont’d)
Data Selection
• March/September -> Equinox
• December -> Winter Solstice
• July -> Summer Solstice
MARCH
Separate Calculations for
Weekends and Weekdays
Exclude Bank Holidays
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

20. Novel Calculation Procedure on Piraeus Port
• Calculate Dimming Levels for every hour
module in Visual Basic (for Excel)
• Count Hours for each level of dimming
01-Mar-13 -0.21424 -0.1936 -0.17297 -0.15236 -0.13177 -0.11121 -0.09068 -0.07019 -0.04973 -0.02933 -0.00898 0.011313
02-Mar-13 -0.20954 -0.1889 -0.16827 -0.14765 -0.12706 -0.10648 -0.08594 -0.06544 -0.04497 -0.02455 -0.00419 0.016123
03-Mar-13 -0.20478 -0.18414 -0.16351 -0.14288 -0.12228 -0.1017 -0.08115 -0.06063 -0.04016 -0.01972 0.00066 0.020988
04-Mar-13 -0.19997 -0.17932 -0.15868 -0.13806 -0.11745 -0.09686 -0.0763 -0.05577 -0.03528 -0.01484 0.005561 0.025906
05-Mar-13 -0.19509 -0.17445 -0.15381 -0.13318 -0.11256 -0.09197 -0.0714 -0.05086 -0.03036 -0.0099 0.010513 0.030874
06-Mar-13 -0.19017 -0.16952 -0.14888 -0.12825 -0.10763 -0.08703 -0.06645 -0.0459 -0.02539 -0.00492 0.015512 0.035889
07-Mar-13 -0.18519 -0.16455 -0.14391 -0.12327 -0.10264 -0.08204 -0.06145 -0.04089 -0.02037 0.000116 0.020557 0.04095
08-Mar-13 -0.18017 -0.15953 -0.13888 -0.11824 -0.09761 -0.077 -0.05641 -0.03584 -0.01531 0.00519 0.025646 0.046053
09-Mar-13 -0.1751 -0.15446 -0.13381 -0.11317 -0.09254 -0.07192 -0.05132 -0.03075 -0.0102 0.010306 0.030774 0.051197
10-Mar-13 -0.16999 -0.14935 -0.12871 -0.10806 -0.08743 -0.0668 -0.0462 -0.02561 -0.00506 0.01546 0.035941 0.056377
11-Mar-13 -0.16484 -0.1442 -0.12356 -0.10291 -0.08227 -0.06165 -0.04103 -0.02044 0.000119 0.02065 0.041143 0.061593
12-Mar-13 -0.15965 -0.13902 -0.11837 -0.09773 -0.07709 -0.05645 -0.03584 -0.01524 0.005331 0.025872 0.046377 0.066841
13-Mar-13 -0.15443 -0.1338 -0.11315 -0.09251 -0.07187 -0.05123 -0.03061 -0.01001 0.010574 0.031125 0.051641 0.072117
14-Mar-13 -0.14917 -0.12854 -0.1079 -0.08726 -0.06662 -0.04598 -0.02535 -0.00474 0.015846 0.036406 0.056933 0.077421
15-Mar-13 -0.14389 -0.12326 -0.10263 -0.08198 -0.06134 -0.0407 -0.02007 0.000548 0.021142 0.041711 0.062248 0.082749
16-Mar-13 -0.13858 -0.11796 -0.09732 -0.07668 -0.05604 -0.03539 -0.01476 0.00586 0.026462 0.047038 0.067585 0.088097
17-Mar-13 -0.13325 -0.11263 -0.092 -0.07136 -0.05071 -0.03007 -0.00943 0.011193 0.0318 0.052385 0.072941 0.093464
18-Mar-13 -0.12789 -0.10728 -0.08665 -0.06601 -0.04537 -0.02473 -0.00409 0.016543 0.037156 0.057748 0.078314 0.098847
19-Mar-13 -0.12252 -0.10191 -0.08129 -0.06065 -0.04001 -0.01937 0.001275 0.021908 0.042526 0.063125 0.083699 0.104242
20-Mar-13 -0.11713 -0.09653 -0.07591 -0.05528 -0.03464 -0.01399 0.006649 0.027285 0.047908 0.068513 0.089095 0.109647
21-Mar-13 -0.11173 -0.09114 -0.07053 -0.0499 -0.02926 -0.00861 0.012032 0.03267 0.053298 0.073909 0.094498 0.115059
22-Mar-13 -0.10632 -0.08574 -0.06513 -0.0445 -0.02387 -0.00322 0.017422 0.038062 0.058694 0.07931 0.099906 0.120476
23-Mar-13 -0.10091 -0.08033 -0.05973 -0.03911 -0.01847 0.00217 0.022815 0.043458 0.064092 0.084714 0.105316 0.125895
24-Mar-13 -0.09549 -0.07492 -0.05432 -0.03371 -0.01308 0.007565 0.02821 0.048854 0.069491 0.090117 0.110726 0.131312
25-Mar-13 -0.09006 -0.0695 -0.04892 -0.02831 -0.00768 0.012959 0.033603 0.054248 0.074888 0.095518 0.116132 0.136725
26-Mar-13 -0.08465 -0.06409 -0.04351 -0.02291 -0.00229 0.018349 0.038992 0.059637 0.080279 0.100912 0.121531 0.142131
27-Mar-13 -0.07923 -0.05869 -0.03812 -0.01752 0.0031 0.023732 0.044373 0.065018 0.085661 0.106298 0.126922 0.147528
28-Mar-13 -0.07382 -0.05329 -0.03273 -0.01214 0.008477 0.029105 0.049744 0.070389 0.091033 0.111672 0.1323 0.152912
29-Mar-13 -0.06843 -0.04791 -0.02735 -0.00677 0.013842 0.034466 0.055103 0.075747 0.096391 0.117033 0.137664 0.158282
30-Mar-13 -0.06304 -0.04253 -0.02198 -0.00141 0.019193 0.039813 0.060446 0.081088 0.101733 0.122376 0.143011 0.163633
Hr 5 6 6 6 6 6 6 6
Mn 55 1 7 13 19 25 31 37
01-Mar-13 0.115163 0.095264 0.075277 0.055208 0.035062 0.014846 -0.00544 -0.02578 -0.04617 -0.06661 -0.08710089 -0.10763
02-Mar-13 0.118828 0.098899 0.078883 0.058786 0.038615 0.018374 -0.00193 -0.02229 -0.0427 -0.06316 -0.08366293 -0.1042
03-Mar-13 0.122484 0.102524 0.082479 0.062355 0.042159 0.021896 0.001571 -0.01881 -0.03924 -0.05972 -0.08022994 -0.10078
04-Mar-13 0.126129 0.106139 0.086066 0.065916 0.045695 0.025409 0.005063 -0.01534 -0.03578 -0.05627 -0.07680232 -0.09736
05-Mar-13 0.129764 0.109744 0.089643 0.069467 0.049221 0.028913 0.008547 -0.01187 -0.03233 -0.05284 -0.07338043 -0.09395
06-Mar-13 0.133388 0.113338 0.093209 0.073007 0.052738 0.032408 0.012023 -0.00841 -0.02889 -0.04941 -0.06996461 -0.09055
07-Mar-13 0.136999 0.11692 0.096764 0.076537 0.056246 0.035894 0.01549 -0.00496 -0.02546 -0.04599 -0.06655515 -0.08715
08-Mar-13 0.140598 0.120491 0.100308 0.080057 0.059742 0.03937 0.018947 -0.00152 -0.02203 -0.04258 -0.06315235 -0.08375
09-Mar-13 0.144184 0.124048 0.10384 0.083564 0.063228 0.042836 0.022395 0.001909 -0.01861 -0.03917 -0.05975646 -0.08036
10-Mar-13 0.147756 0.127593 0.107359 0.08706 0.066703 0.046291 0.025833 0.005332 -0.01521 -0.03577 -0.0563677 -0.07698
11-Mar-13 0.151314 0.131124 0.110866 0.090544 0.070166 0.049736 0.029261 0.008745 -0.0118 -0.03238 -0.05298629 -0.07361
12-Mar-13 0.154858 0.134642 0.114359 0.094015 0.073617 0.053169 0.032678 0.012149 -0.00841 -0.029 -0.04961241 -0.07024
13-Mar-13 0.158387 0.138146 0.117839 0.097474 0.077056 0.056591 0.036084 0.015542 -0.00503 -0.02563 -0.04624622 -0.06688
14-Mar-13 0.161902 0.141635 0.121305 0.100919 0.080483 0.060001 0.03948 0.018925 -0.00166 -0.02226 -0.04288786 -0.06352
15-Mar-13 0.1654 0.145109 0.124758 0.104352 0.083897 0.0634 0.042865 0.022298 0.001705 -0.01891 -0.03953745 -0.06018
16-Mar-13 0.168884 0.148569 0.128196 0.10777 0.087299 0.066786 0.046238 0.025661 0.005059 -0.01556 -0.03619509 -0.05684
17-Mar-13 0.172351 0.152013 0.13162 0.111176 0.090687 0.07016 0.0496 0.029013 0.008403 -0.01222 -0.03286087 -0.0535
18-Mar-13 0.175803 0.155443 0.135029 0.114567 0.094063 0.073522 0.052951 0.032354 0.011737 -0.00889 -0.02953487 -0.05018
19-Mar-13 0.179238 0.158856 0.138423 0.117944 0.097425 0.076872 0.05629 0.035685 0.015061 -0.00557 -0.02621712 -0.04686
20-Mar-13 0.182656 0.162254 0.141803 0.121308 0.100775 0.080209 0.059617 0.039004 0.018376 -0.00226 -0.02290768 -0.04355
21-Mar-13 0.186059 0.165637 0.145168 0.124657 0.104111 0.083534 0.062933 0.042313 0.02168 0.001038 -0.01960658 -0.04025
22-Mar-13 0.189444 0.169003 0.148517 0.127992 0.107433 0.086846 0.066237 0.045611 0.024974 0.00433 -0.01631383 -0.03695
23-Mar-13 0.192813 0.172354 0.151852 0.131313 0.110742 0.090146 0.06953 0.048899 0.028258 0.007614 -0.01302945 -0.03367
24-Mar-13 0.196165 0.175689 0.155171 0.134619 0.114038 0.093433 0.07281 0.052175 0.031532 0.010888 -0.00975343 -0.03039
25-Mar-13 0.199501 0.179007 0.158476 0.137912 0.11732 0.096708 0.076079 0.05544 0.034796 0.014152 -0.00648578 -0.02711
26-Mar-13 0.202819 0.18231 0.161765 0.14119 0.120589 0.09997 0.079336 0.058695 0.03805 0.017408 -0.00322649 -0.02385
27-Mar-13 0.206121 0.185597 0.165039 0.144453 0.123845 0.103219 0.082582 0.061938 0.041294 0.020654 2.44463E-05 -0.02059
28-Mar-13 0.209406 0.188868 0.168299 0.147703 0.127087 0.106456 0.085816 0.065171 0.044528 0.023892 0.003267047 -0.01734
29-Mar-13 0.212674 0.192123 0.171543 0.150938 0.130316 0.109681 0.089038 0.068393 0.047752 0.02712 0.006501318 -0.0141
30-Mar-13 0.215925 0.195362 0.174772 0.15416 0.133531 0.112893 0.092248 0.071605 0.050966 0.030339 0.009727268 -0.01086
Hr 18 18 18 18 18 19 19 19
Mn 31 37 43 49 55 1 7 13
exact hours of sunrise and sunset during March
• Calculate exact Dimming Percentages
Luminance levels as per
BS EN 13201/2015:2
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
Calculation Procedure
• Identify the Variable Lighting Classes depending on the traffic flow

21. Threshold Comparison with TR27
IN DAILY BASIS
1ST THRESHOLD 15000
2ND THRESHOLD 7000
IN HOURLY BASIS (TR 27)
1ST THRESHOLD 1500
2ND THRESHOLD 700
IN HOURLY BASIS
(PROPOSED METHOD)
1ST THRESHOLD 1000.3
2ND THRESHOLD 472
Calculated thresholds of road lighting in daily and hourly basis
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

22. Threshold Comparison with PLG08
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

23. Threshold Comparison with PLG08
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs
When applying only the BS thresholds of
7000 and 40000 ADT
When applying an interim threshold of
25000 ADT
Luminaires dimmed to 75% output
between 00:30 and 05:00
Luminaires dimmed to 75% output
between 21:00 and 00:30
Further dimmed to 50% output
between 00:30 and 5:00

24. Variable Lighting Levels
Measuring
position
Lighting Class Variable lighting
classes
699 ME4 ME5
730 ME4 ME5
732 ME3 ME4 ME5
735 ME4 ME5
738 ME4 ME5
742 ME4 ME5
747 ME4 ME5
748 ME4 ME5
749 ME3 ME4 ME5
751 ME4 ME5
757 ME3 ME4 ME5
763 ME3 ME4 ME5
Measuring
position
First Dim Second Dim
699 33.33% -
730 33.33% -
732 25.00% 50.00%
735 33.33% -
738 33.33% -
742 33.33% -
747 33.33% -
748 33.33% -
749 25.00% 50.00%
751 33.33% -
757 25.00% 50.00%
763 25.00% 50.00%
Calculated variable classes on all roads and exact dimming regimes
Including the interim ADT values
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

25. Passive Dimming Control Strategy
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

26. Dynamic Dimming Control Strategy
01-Mar-13
04-Mar-13
05-Mar-13
06-Mar-13
07-Mar-13
08-Mar-13
11-Mar-13
14-Mar-13
15-Mar-13
19-Mar-13
20-Mar-13
21-Mar-13
22-Mar-13
26-Mar-13
27-Mar-13
28-Mar-13
29-Mar-13
Date 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 02:00 03:00 04:00 05:00 06:0000:00 01:00
←
OFF
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

27. Comparison of Strategies
LEVELS OF
DIMMING
HOURS
Time-
scheduled
Real-time
No Dimming 69h 16min 57h 16min
25% of Dimming 38h 26min 37h 26min
50% of Dimming 84h 46min 97h 46min
3% further energy savings when applying
the second strategy.
01-Mar-13
04-Mar-13
05-Mar-13
06-Mar-13
07-Mar-13
08-Mar-13
11-Mar-13
14-Mar-13
15-Mar-13
19-Mar-13
20-Mar-13
21-Mar-13
22-Mar-13
26-Mar-13
27-Mar-13
28-Mar-13
29-Mar-13
Date 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 02:00 03:00 04:00 05:00 06:0000:00 01:00
←
OFF
Time-scheduled Real-time-data
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

28. Remarks & Future Considerations
• TR27 wisely superseded by PLG08
• Further consideration is recommended for the proposed transition
levels of PLG08
• Passive dimming strategy provides 29% overall energy savings
• Dynamic dimming control strategy can offer a further 3% energy
savings
• Consideration of cost installation and Payback period calculation prior
to application of the second control strategy
• The proposed calculation procedure has now been validated on
further case studies and annual dimming profiles have been created.
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

29. Acknowledgements
Mr Peter Raynham,
Senior Lecturer
UCL
Best Written Paper
Young Lighter of the Year 2016
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs

30. Variable Lighting Levels for Highways
A Different Approach
Sofia Tolia MEng, MSc
Lighting Engineer, Ringway Jacobs
sofia.tolia@ringwayjacobs.com
ILP Summit
14.06.2017
Sofia Tolia
Ringway Jacobs