Lighting the Corridors

The City of South Bend has unveiled a West Side Corridors Plan, to which I propose three simple guidelines be added:

  1. All outdoor lighting should be full cutoff, or fully shielded.

  2. If LED lights are used, they should be under 3000K.

  3. Lights should minimize glare, sky glow, and light trespass.

If the residents in a neighborhood want lighting, give them lighting--but make it both sufficient and sensible. These same principles apply to other city-wide projects, like Light Up South Bend and Lamp Post Project.

Persons who select lighting fixtures often are making decisions by day based on the content of manufacturers' catalogs, or they misunderstand what constitutes the most beneficial lighting. Many manufacturers purport to offer a dark-sky friendly fixture, when in fact they diminish security rather than improve it.

Choose Full Cutoff

Better options are available. For example, the lights proposed for the West Side Corridors Plan are the Lake Bluff model (1910 / 5LB) manufactured by Sternberg Lighting, which has "a glass like acorn" that visibly sags below the aluminum shade and scatters light. A better choice would be the same company's similar Mission Trails model (1950), which fully cuts off light because the lens is tucked up in the shade, thus not hindering your view with glare.

While the city claims in its Lamp Post Project application that "the lamps (are) designed to prevent 'sky glow,'" the three fixtures selected instead are glare-intensive with exposed bulbs, and the project offers no option for a safer glare-free fixture. I say "safer" because glare hinders your vision, especially for aging eyes. In essence, the direct light creates darker adjoining areas, as perceived by your eyes, thus reducing the desired effect. With an exposed light next to your face, try looking beyond into the dark. Every exposed light source has the same effect, causing your pupil to constrict and to let in less useful light.

To the city's credit, section 5.1.7 Street Lights of the West Side Corridors plan advocates that "lighting for commerial purposes should be appropriately shielded to minimize spillover to residential areas."

Ornamental Red Flag

Later, in Section 5.2 Residential Streetscape, the plan advises "ornamental street lights should be used." For me, the seemingly charming "ornamental" is a red flag, for, again, the selection will likely be made based on catalog images and not based on how well the lighting scheme serves the individuals at night.

A recent example of good intentions gone bad is the new Beacon Parkway in Mishawaka, which opened in April 2015. The new 4,000-foot road was touted in a South Bend Tribune article as having a "park-like feel with ornamental LED street lights and newly planted trees." Of course, that was the daytime view being reported. If birds want to sleep at night, I doubt they'll be roosting in those trees. By night the intensity and whiteness of the glare is downright egregious and hard on the eyes.

Avoid the Blues

The description "ornamental LEDs" brings up another red flag--LED lights. Everyone is eager to jump on the LED bandwagon, for LEDs certainly use less energy and last longer. I'm all for that. However, a consumer needs to be selective in which LEDs are purchased, for they are not all equal. There is plenty of research (I usually cite Seeing Blue for its summary of the issues) to show how blue-rich light, found in many LED applications, is harmful to human health. That's without even getting into its impact on the rest of the animal kingdom. (Blue-rich lights also cause several-fold the amount of sky glow than, say, a comparable output of sodium vapor lights because the shorter wavelength of blue scatters more than red.)

Basically, certain functions of your body need darkness--its an artifact of how we've evolved through eons of day and (dark) night--and your body is sensitive to bluer wavelengths of light. You want blue by day, but not at night. I describe this in more detail in several talks I've given in the community, which you can find in the red bar of my Dark Skies page.

The solution is easy. If you must buy LEDs for nighttime applications, buy LEDs that are not blue-rich. How can you tell the difference? It's like buying "warm" or "soft" light bulbs instead of "cool" or "daytime" light bulbs. You know the difference. With LEDs, check the label (even if you're a city buying streetlights) and get the redder LEDs that are under 3000K (temperature is a reflection of color). Do not get blue-rich LEDs that are 5000K.

While the city is at it, if it strings together a bunch of LED street lights, the city should consider another new benefit of LED technology--connecting LED fixtures to electronic dimmers. You compound your energy savings while gaining the many upsides of less harsh lighting during low-use hours.

Do Right

Some get it. In Michiana, for example, developers of Eddy Street Commons and Toscana Park get it. Check out much of their original lighting. St. Joseph County's road improvements have lately been fitted with full cutoff lights (right). The jury is out on other jurisdictions as they install a mix of appropriate and lousy lighting.

Do the right thing for the people along the corridor. Buy the right fixture that serves them best--for security, for safety, for health, for aesthetics, for efficiency. Don't dump a poor solution in the name of "giving them the lights they asked for."

Summary

  • Buy lights that are full cutoff. Not cutoff or semi-cutoff. Full cutoff. There's a difference.

  • If buying LEDs, avoid the blue-rich lights and choose a less harsh option that's rated under 3000K.

  • In all efforts, strive to avoid the three biggest laments of light pollution--glare, sky glow, and light trespass. If a community needs light, give them quality light rather than dumping the cheapest product on them.

  • Choose lights by how well they function, not by how well they look in a pretty catalog picture.

  • Product descriptions are not always reliable, and claims of being "dark sky" fixtures are loosely thrown around (see wall pack light description, right).

  • If you have questions about large-scale lighting plans in Michiana, contact me if you want an opinion. I have a vested interest in seeing it done right here. A little dialog may only cost you a cup of coffee. Thanks for your consideration.

Thanks to Michael Divita of the City of South Bend Department of Community Investment (Planning Team) for receiving these comments about the West Side Corridors Plan.

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