This is my home in San Diego at approximately 11PM in March. The decorative post-top street light in front of our house illuminates my front yard and the front facade of my house. We installed thick wood blinds to keep the light out. See the shadow of the narrow tree next to my daughter's window? It's a lot of light.
Quality of life isn't the only reason for installing the right illumination where it is needed. It also results in a lower electricity bill for the City, a decrease in greenhouse gas emissions, lower maintenance costs, and extends the luminaire's life. This intrusive illumination is just one example of poor light management.
We can do better.
Smart cities take the entire population at all times of the day into account when designing city infrastructure. From bike lanes to 5G, cities around the world are partnering with their citizens to provide a safe, energetic, and functional world for everyone, while saving energy and reducing excess light pollution.
What does this mean when the sun sets? Cities are applying smart design thinking to light! Outdoor lighting design needs to support both the quiet time of the night as well as the economic activity of our most vibrant neighborhoods. The traditional method of street light design is based on a flat world using a cookie-cutter approach. Technology from outside the engineering world can bring powerful insights resulting in not only better design but also community input and buy-in.
Geography Meets Lighting
Geographic Information Systems (GIS) has a long history of providing planning and asset management solutions for electric, gas, transportation, construction, and many other infrastructure providers. While street lighting has long been considered an electric asset, the actual illumination these systems produce has never been comprehensively managed. Leveraging the same technology used to manage electric assets, light can also be managed.
There is significant untapped utility in understanding how artificial/electric outdoor light illuminates our communities. Electric light not only illuminates streets and roads for drivers, but also bike lanes, crosswalks, and sidewalks for pedestrians and everyone using the right-of-way. Even outdoor dining is impacted by lighting. Major advancements in lighting designs have increased the options for cities. Unlike legacy lighting, modern LED lighting is directional. All light should have a clear purpose and be directed only to where it is needed.
Current State of Lighting Design
Lighting and energy professionals use lighting software to design typical intersections and roadway segments. The results are then extrapolated across the City or region. For example, the design of a typical local/collector intersection is applied to all local/collector intersections across a project area. Yet a myriad of local/collector intersections will substantially deviate from the typical layout used during the design process, including areas of high slope, bike lanes, intersections that meet at irregular angles, non-standard road widths, roads that curve, street light mast arms in abnormal directions, parking lanes, medians and more. These deviations are often not accounted for in typical applications. An illumination layer within a GIS can bring together details of the natural and built world for better lighting decisions.
Geography, Technology, and the Real World
Instead of a cut-and-paste approach to lighting design, the lighting data can be easily ingested into a GIS and brought to life. An immediate benefit is viewing illumination data across an entire region in a graphic, easy-to-use, web-based map for the first time.
To get technical for a moment, files in standard IES format for lighting can be run on hundreds or hundreds of thousands of street lights and different IES files can be used at each luminaire in the same comprehensive GIS model. GIS brings a comprehensive approach to lighting design. What does this mean for cities? Illumination data can be viewed and analyzed in a realistic model of the real world. Lighting professionals and project stakeholders can view and explore lighting designs across multiple scales, from a single light to an entire region. Below is a single post top street light (similar to the light at my house.)
GIS Brings New Insights
GIS processes complement the best practices in lighting design by placing professional designs on a 3D map, enabling lighting professionals to account for elevation changes and circumstances that deviate from generic, one-size-fits-all representative “runs.” GIS brings new datasets that bring context to light.
In addition, other GIS datasets, such as roadway average daily traffic counts, roadway classifications, bike lanes, crime data, protected species habitats, landuse and zoning designations, and many others can be analyzed for deeper insights and answer such questions as:
- Are there any endangered species nearby that might be harmed by the light?
- Where are nighttime transportation safety concerns?
- Are there areas which should be illuminated to encourage economic activity?
GIS streamlines the identification of these issues across a large outdoor lighting project.
Lighting data leaving a fixture above 1 lux can be accurately calculated by viewing an illumination model in 3D. Adding additional GIS datasets, such as roadway traffic volumes, counts, classifications, active mobility corridors, crime data, and protected species habitats, can help create a more accurate picture.
Smarter Design Means Better Outcomes
A more accurate and realistic lighting design offers many benefits, including:
- Better conditions for walking and biking using smart lighting decisions along high-injury networks or high nighttime collision areas.
- Appropriate lighting for protected habitats by lowering color temperatures, using different wattages, shielding, or even removal of lighting.
- Fairer use of lighting in regional equity measures to ensure all populations are illuminated in an equitable manner.
- Collaboration and involvement of stakeholders by sharing a holistic view of lighting designs via a modern web-based map interface.
- Streamlines outreach efforts by supporting displays and presentations to elected officials as well as other visualizations designed to facilitate project understanding and impacts.
Smart cities and utilities understand their responsibility to manage light. Light helps us get home, brings customers to our businesses, quiets our neighborhoods at night, and provides safety. By combining the power of GIS and the expertise of lighting professionals, cities can turn light into one of their most important assets.