HomeMy WebLinkAbout2016-07-12-CSDRC-min
Town of Lexington
Center Streetscape Design Review Ad Hoc Committee
Thursday July 12, 2016
Parker Room, Lexington Town Hall
8:00 am to 10:00 am
The meeting was called to order at 8:15 AM. Attendees were welcomed and asked to sign in and
provide contact information.
The meeting began with an overview of the Draft Work Plan for the committee that identified
meeting dates and agenda items, with a goal of being ready for the first tier recommendation in
mid-September (first tier is pavements and lighting). A discussion ensued as to when would be
the best time for an evening meeting. While all Committee meetings are public meetings, Mark
Connors noted it might be a prohibitive time for some. It was decided that the Ad Hoc
Committee needed to formulate some basic recommendations that would then go to the
Selectmen. Public input beyond the Ad Hoc public meetings could happen then. It was
discussed that each tier recommendation that the Committee prepares is a DRAFT, and the
committee will finalize its work at the end of the entire process. A late October evening meeting
was discussed as a possibility. Jon Himmel volunteered to act as chair for the 9 August meeting.
John Livsey of the Lexington Department of Public Works began the technical presentation
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on lighting.
Lighting is for road and pedestrian safety, but it also encourages evening street life and
business, and it reduces the effects of headlight glare. Many factors go into the ideal street
lighting. Height is critical. John described the Golden Ratio in design of 3 high by 5 wide
and that it can be aesthetically pleasing for light placement/height. This refers to the pole to
pole length down a side of the street.
John explained that lighting as a science began in the 19th century. Some of the important
terms include Candela, which is the light a common candle emits. So a foot candle is the
amount of illumination from one candle, one foot away, projected on a foot square.
Illuminance is the rate of flow of light that lands on a surface and is measured in foot candles
or lux. Lumens per square foot is foot candles. Distance and angle determine illuminance.
Luminance is the light that comes off a surface, what you actually see. Grass reflects three
times more than standard asphalt. Standards for street lighting have evolved from
illuminance to luminance (see Illuminating Terms and Graphics).
Illuminance superimposed on the eye can cause disabling glare. If you eliminate contrast
you have not improved visibility. Different luminaires (lights) produce different
illumination.
STV or Small Target Variable is the new standard in public lighting. You don’t want to vary
contrast that much along a road. Positive contrast tends to assist car headlights. Neutral is
where you have no contrast and so not good visibility.
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There are different colors of light to consider. Blue headlights are increasingly common and
the younger population prefers blue light. White light, closest to moonlight, works well with
plant material. Yellow light is preferred by the elderly, especially those with cataracts. LED
lights are now very controllable. Chromaticity is lighting color and relates to Kelvin. 4,000
range Kelvin white light is preferred. Higher Kelvin gets you into the blue range.
John Livsey stated that good light is the proper amount for the task, uniformity, proper color,
good contrast. Luminaires have different net distributions to be chosen. There’s uplight into
the sky (undesirable), backlight which is projected behind the light fixture, and forward light
that follows the focus of the luminaire. The light that projects off 10° is the most damaging
uplight. Various cutoffs control the uplighting.
Pam Shadley, Committee member, began her lighting choices presentation.
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She stated that lighting design must find the balance between the technical needs, the client
needs and the budget. She stated IES (Illuminating Engineering Society) standards establish
the illumination levels recommended for different kinds of spaces, and we should use these
standards for this project.
She noted you cannot do a photometric plan until you pick a light, and you cannot light all
six lanes of Mass Ave in Lexington Center without tall lights. On the north side, we will
probably need additional lighting for the sidewalk. Trees must be calculated in as they are
light-blockers. There are many choices of light styles.
Pam shared cut sheets on several light types and pointed out we must choose the base, the
pole/shaft and the luminaire. She shared several Spring City fixtures and suggested
committee members review that line for traditional fixtures. We, as the clients, have to
decide the style. She pointed out a Bishop’s Crook style, and several others, and
recommended we also look at Philips GE lighting for LED contemporary fixtures. At first,
LED produced very hot, glaring light, but now they have softened the light. They are cost
effective, and many good products are available.
She showed an example of the modern ‘Roadstar’ light (see Illuminating Terms and
Graphics) which is designed to effectively disappear visually. It is the pedestrian lights that
we ‘see’. She said you usually take tall lights and stagger them down the roadway to
illuminate the vehicular way, then infill with pedestrian-scale lights.
Someone asked if there is a rule of thumb in terms of cost, for fewer and taller fixtures? Pam
replied yes, more fixtures equal more cost. She reiterated that we cannot light the road
without a taller fixture due to its width. Susan Bennett, Director, Lexington Historical
Society, stated that we need to coordinate with and create harmony with the design decisions
being made for the Battle Green. She noted around the Battle Green now there are many
different light styles.
Pam, when asked, explained the difference between a roadway light (on an arm) versus a
pole top light. She said the project can use a mix as is desired. She said that one option is to
use modern lights to light the roadways, and more traditional fixtures to light the sidewalks
and pedestrian ways. There are many, many options to consider.
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Mark Connors asked if we could preserve the existing Sasaki lights. John Livsey said they
could not be rewired or salvaged. They cannot be upgraded. However, there may be new
LED lights that are in sympathy with the Sasaki design, and this can be looked into.
A member of the public asked if the existing lighting on the north side met photometric
requirements. The answer to this is unknown, but the illumination levels may not meet
current standards. Pam suggested you can download an app to measure illumination (a light
meter) and you can judge the foot candles for yourself. It would be good for us to have an
understanding of how different illumination levels feel. She noted you don’t necessarily
want over-lighting; .5 foot candles for a bikeway, 1-2 foot candles on sidewalks, 2-4 foot
candles on a roadway and at intersections.
Mark Connors gave a presentation on the historic vision of Lexington Center.
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Most people think of the Lexington Battle as historic Lexington and we value that time
period, like the Buckman Tavern. But Lexington has continued to develop. The train was
transformational and we also value the Depot. The train and street trolleys transformed
Lexington into a streetcar suburb and much of the farmland was then developed into housing.
Even the Post Office is a listed historic building. He shared a photo from the 1800’s with
horse and carts. Another from the early 1900’s showed the Center buildings now taller. In a
photo of Depot Square from the 1930’s the taller buildings, cars and diagonal parking has
evolved the space again. Mark felt the diagonal parking had determined the width of Mass
Ave. The Center was very retail focused.
Housing and density increases the liveliness of the Center. There used to be actually more
stores and businesses, and more variety.
Mark noted that post World War II was another time of growth and transformation for the
town. 128 as we now know it was built, as was the Burlington Mall. Lextopia, a
presentation by the Historical Society, documented that in the early 60’s there was an
architectural focus on modernism. Our town has the highest density of modern homes in the
Northeast. So, not just colonial. You can value many historical times.
The postwar changes triggered the planning for Lexington Center. They wanted, in the face
of malls and cars, to maintain the vitality of the Center and also to tie it back to our history.
The decision was made to give up street width and to create wider sidewalks for a promenade
and livingroom-like space on the north side of Mass Ave.
Hideo Sasaki, a Lexington resident and Landscape Architect, led the team. He used many
case studies from around the world including Ramblas in Barcelona, and the Champs
Elysees, in Paris. Sasaki wanted to create a linear park with almost a canyon feel. A double
line of trees in the case studies created that space. Then he wanted little eddies for gathering,
with street furniture, seating, and amenities.
Mark Connors ended with modern photos of the Sasaki-designed Center and noted how
many of the barrier plantings have died and/or are neglected. They can no longer serve their
protective purpose. He reiterated how critical maintenance is and that we can revitalize the
original design and not destroy it.
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He shared a Hideo Sasaki quote.“As the world becomes more crowded and resources
limited, we must treasure the oases we find and create new ones, no matter how small, with
love and care.”
GRAPHICS THAT WERE PART OF THE DISCUSSION:
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