A Guide to National Sign-I llumination Standards AMERI CAN PLANNI NG ASSOCI ATI ON 2017 NATI ONAL CONFERENCE SESSI ON # 9110381 Philip Garvey, University Park , PA Alan Weinstein, Cleveland State University, Cleveland, OH Donald Poland, AICP, Hartford, CT Richard Crawford, United States Sign Council, Bristol , PA
Session Outline I ntroduction Sign lighting from the perspective of the Researcher Sign lighting in Practice Sign lighting from a Code and legal perspective Sign lighting from a planner’s perspective
Housekeeping A. Please mute cell phones B. Questions will be at the end
Sign lighting from the perspective of the researcher “ Well-designed sign lighting can aid the driver in rapid, accurate recognition and understanding of the sign’s message. This serves to improve safety by reducing the possibility that motorists will stop or drastically reduce speed at signs that may otherwise be difficult to read. ” - IES
Regulating Sign Brightness 1. Light Pollution 1. Sign Visibility
Light Pollution Existing Recommendations ILP (2014) IESNA (2011)
Sign Legibility “The ability to see, and light trespass/objectionability are essentially unrelated.” - Luginbuhl
Background • In 1994, Penn State began working with The United States Sign Council on improving the visibility of Commercial On-Premise Signs. • To improve sign visibility and increase driver safety , we have conducted eight studies related to optimizing sign lighting.
PSU/USSCF Sign Lighting Research Lighting and Color (Test Track) 1998: Effect on Legibility • Font type (Helvetica and Clarendon) • Text and background color • Lighting design (external/internal/neon) General Conclusions: Internal illumination and neon outperformed external illumination.
PSU/USSCF Sign Lighting Research Light Pollution (Open Field) 2004: Addressed the actual and perceived effect of varied types of illuminated signs on the dispersion of light in the nighttime environment. Concluded that on-premise signs have minimal effect when current norms of measurement for light trespass, sky glow, and glare are employed.
PSU/USSCF Sign Lighting Research Lighting Design (Test Track) 2004: Internally vs. Externally Illuminated
PSU/USSCF Sign Lighting Research Lighting Design (Open Field) 2010: Internally vs. Externally Illuminated
PSU/USSCF Sign Lighting Research Internally vs. Externally Illuminated General Conclusions: Test track and open field tests show that internal sign illumination, on average, provides 40% greater visibility and 60% greater legibility than that provided by external sign illumination. Easier to control “spill light” with internally illuminated signs.
PSU/USSCF Sign Lighting Research Sign Brightness (Test Track) 2008: Optimal Internally Illuminated Sign Brightness Levels
PSU/USSCF Sign Lighting Research Sign Brightness: cd/m 2
PSU/USSCF Sign Lighting Research Metric units is the standard in lighting research and design and is used exclusively by the CIE, Institute of Lighting Professionals (ILP, formerly ILE), and IES. SI (Metric) vs. English Units: Luminance: cd/m 2 (same as Nits) vs. Footlambert (ft-L) Illuminance: Lux (lx) vs. Foot-candle (ft-c)
PSU/USSCF Sign Lighting Research EMC Lighting Levels (Analytic and Test Track) 2015: Optimal Brightness Levels
PSU/USSCF Sign Lighting Research EMC Lighting Levels:
PSU/USSCF Sign Lighting Research Channel and Cabinet Sign Lighting Levels (Laboratory) 2016 Measurement of Typical Sign Luminance/Illuminance Levels
PSU/USSCF Sign Lighting Research Channel and Cabinet Sign Lighting Levels 243 Sign Conditions: 25 Colors in Positive and Negative Contrast, Single-Face/Double- Face/Channel Letter
PSU/USSCF Sign Lighting Research Factors Impacting Illuminated On-Premise Sign Visibility at Night (Analytical) 2017 Review of Existing Literature on Optimal On-Premise Sign Brightness General Conclusions: • Luminance, not Illuminance, is the measure of choice: – Luminance is independent of sign size and viewing distance. – Luminance is the photometric equivalent of brightness and therefore is the metric associated with sign visibility. – Luminance meters are not affected by changing ambient light. – Illuminance meters may not be sensitive enough to distinguish between measurements taken with the “sign on” and the “sign off.” – Luminance is the standard used by EMC manufacturers in specifying sign lighting levels. – Both the IESNA and the CIE specify road sign lighting in terms of luminance values. – “Luminance is the best measure available to judge relative sign brightness.” – 3M
PSU/USSCF Sign Lighting Research Factors Impacting Illuminated On-Premise Sign Visibility at Night General Conclusions (continued): • While there has been a great deal of research on the topic, there are still a number of critical unanswered questions, in part due to the dramatic and rapid changes in sign lighting technology and in part to the differences in measures of effectiveness. • While the measurement techniques and metrics are clear, it is also clear that further research is necessary to identify the optimum luminance level for on-premise commercial signs from a sign visibility/traffic safety perspective.
Future Sign Lighting Research • Using LEDs in cabinet and channel letter signs to develop clear minimum, optimum, and maximum nighttime brightness levels based on sign visibility. • Optimal EMC Lighting Level for Visual Performance using Objective Measures of Legibility. • Commercial Sign Performance In Complex Visual Backgrounds • The Relationship Between Sign Luminance and Sign Contrast • The Impact of Commercial Sign Brightness on Transient Adaptation • Open-Field Study on the Tradeoffs between Sign Detection and Legibility and Sign Brightness Levels
Sign Lighting in Practice Richard B. Crawford, Esquire United States Sign Council & United States Sign Council Foundation, Bristol PA Mercer Sign Consultants, Doylestown PA
Current USSCF Research • 1) ENVIRONMENTAL IMPACT OF ON-PREMISE SIGN LIGHTING, With Respect to Potential Light Trespass, Sky Glow, and Glare (2004) • 2) RELATIVE VISIBILITY OF INTERNALLY AND EXTERNALLY ILLUMINATED ON-PREMISE SIGNS (2004) • 3) INTERNALLY ILLUMINATED SIGN LIGHTING, Effects on Visibility and Traffic Safety (2009) • 4) INTERNAL vs. EXTERNAL ON-PREMISE SIGN LIGHTING, Visibility and Safety in the Real World (2009) • 5) ON-PREMISE SIGN LIGHTING, Terms, Definitions, Measurement (2010) • 6) ON-PREMISE ELECTRONIC MESSAGE CENTER LIGHTING LEVELS: Phase 1 and Phase 2 (2015) • 7) STANDARD LUMINANCE LEVELS OF ON-PREMISE SIGNS (2016)
Scope of Standards On-Premise Signs Covers both “static” and electronic signs No billboard/off-premise/outdoor advertising signs
issues Reed eed v Gilber ert A science-based and research-based approach to sign regulation will become even more critical, post- Reed , and the USSC Sign Lighting Best Practices Standards can be a valuable tool going forward
How sign lighting is currently regulated 1. No sign lighting regulation 2. Brightness standard 3. Light trespass standard / Nuisance standard 4. Energy conservation standard
Time-out
Light trespass standard / Nuisance standard Energy conservation standard
Types of Signs Internal Illumination
Types of Signs External Illumination
Types of Signs Direct Illumination
Static Signs EMC / Electronic / Digital Signs
The Focus of all USSCF Research Traffic Safety & the need of the Driver Key Fact: On-premise signs need to be visible and legible for drivers from a distance, which, depending on posted speeds, can range from 250’-0” to 800’-0”, and beyond = 6-10 seconds
Lighting Terms There are (2) systems of terminology SI/Metric terms vs English terms Key Fact: don’t mix terminology; metric values are higher vs English values.
Guideline Standards Use the SI/Metric terms Luminance - A unit expressing the brightness of the source Basic unit is a “Candela” Candelas per meter squared (Also known as “nits”) = cd/m²
Guideline Standards Do not use the English terms nor Illuminance - a unit expressing amount of light falling on a place or object; SI (Metric) Term English Term: Lux One lux is equal to one lumen per square meter.
Conversions are possible See Page 16 Luminance = E x D / [Area of sign] E is the sign illuminance in lux SI (metric) D is the distance from the sign where the illuminance was measured in meters squared (m² ) SI (metric) Area of the sign is in meters squared (m² ) SI (metric) Example: 5 lux reading x 441 m² (21 meters squared or 70 FT) / 3.71 area in meters squared (40 SF) area Yields a sign luminance at night of 594.34 nits or cd/m²
Brightness Standard The USSC Sign Illumination Guideline Standard for maximum sign brightness at night: Illuminated sign brightness shall not exceed the maximum luminance level of seven hundred (700) cd/m² or Nits at least one-half hour before apparent Sunset……….
Recommend
More recommend
