R. Bouwmeester & Associates, a civil engineering firm, provides specialized sun and shadow position modeling services related to traffic collision and crime scene reconstruction, and urban development, site planning and building design projects.
In the April 1, 2010, edition
of the Omaha World-Herald, staff writer Nancy Gaarder spoke of the early morning
sun blinding those driving to work at this time of year. To read the
World-Herald article, click here. For
similar articles on this topic, see our Site Map.
During a telephone interview
with Ms. Gaarder, we were asked to explain why sun glare is such a problem at
this time of year in so many cities. There are several reasons.
The sun rises and sets in
line with east-west streets at this time of year
Since the sun rises and sets
in an east-west direction at the beginning of spring and fall (around March 21
and September 21), and given the east-west / north-south orientation of street
grids in so many cities, the sun just so happens to rise and set in line with
east-west streets at those times of year. After the change to Daylight Saving
Time on the second Sunday in March, sunrise occurs one hour later, namely,
around 7:30 a.m. CDT or so in the Omaha area, that is, during the thick of the
While the spring and fall
present challenges for drivers on east-west streets at sunrise and sunset, other
street directions will be equally challenging at other times of year. Note that
in Omaha the sun rises and sets more or less northeast and northwest during
summer, and southeast and southwest during winter. Drivers should always make
themselves aware of where the sun is or where it might be as they round a curve
or crest a hill.
Living west of your place
of work means commuting into the sun morning and night
In cities such as Omaha where
a large number of commuters live west of downtown, "a significant number of
commuters are driving directly into the sun" during the morning commute in
spring and fall. And the evening commute home can be equally
Cooler temps mean less
haze and brighter sun
Another factor that adds to
the intensity of the sun's glare during spring and fall is that temperatures are
generally cooler resulting in an atmosphere that is less humid and
First and last hour of
daylight most dangerous
Sun glare seems to be most
problematic for drivers during the first and last hour or so of daylight. At
least this appears to be the trend in traffic accident cases we have been
involved with. There are exceptions - in fact, visibility can be compromised
anytime the sun is shining and particularly when it lies within the field of
view of one's windshield. Generally speaking, the closer the sun gets to one's
line of sight to an object, say another vehicle or a pedestrian, traffic light
or stop sign, the more difficult it will be to detect the object. But it should
also be noted that sun glare is not only a problem when the sun lies ahead -
traffic signals and brake lights can be "washed out" when it shines from
Be especially cautious
when the sun is behind you
A special word of caution to
drivers and pedestrians alike - if you see your shadow or the shadow of your car
straight ahead of you in the road, you should assume that oncoming drivers are
having difficulty seeing you. In other words, be extra cautious when the sun is
behind your back and your shadow points toward an oncoming vehicle. Pedestrians
can be fooled when the front of an approaching vehicle is lit up brightly by the
sun - however, chances are the driver cannot see you very well. Be aware and be
safe - assume they cannot see you at all!
Ralph Bouwmeester calculates how
proposed buildings will limit the sunlight on
BY GUY BABINEAU - NATIONAL POST
PETER J. THOMPSON / NATIONAL POST
Blinded by the light: Bouwmeester's program determines
the shadow that would be cast anywhere in the world.
It is enough to make you tear out your hair. A couple of years ago, you found a new townhome that was just perfect for you. It was centrally located, close to transit and shopping and came with a host of amenities that suited your lifestyle to a tee. The spring day you viewed it was clear and sunny, showing off the freshly landscaped exterior to advantage. The sunlight shone warmly on the freshly painted walls of a charming outside back patio, the outstanding feature that sold you on the place. Then, a year later, yikes.
The bulldozers came. They razed an entire row of old houses right behind your complex and up went a new condo building, situated in such a way that now it casts a shadow over your patio during the peak hours of summer sunlight, and your next-door neighbour's, too. The thing is, both you and your neighbour are at the end of the complex and it is pretty obvious that if they had made a few simple adjustments to the condo, you would still have your sunny patio and everyone would be happy. It is too late now. How come someone didn't do an analysis to figure this out before they built the damn thing?
If something like this has not actually happened to you, it has quite likely happened to someone you know. There are variations on the theme: The new monster home wedged into a street of older homes, casting permanent shade over the next-door neighbour's once-sunny breakfast nook; a house addition that looms over what was once the adjacent property's rose garden, now planted with gloom-loving ferns - you get the picture.
While architects and builders generally take into consideration the shadow impact of a new development or addition, often the method they use to figure out what is called "sun positioning" is based on generalized sunlight tables that cover a large geographical area. Site-specific sunlight projections can be askew. The discrepancy seems subtle on paper but the ramifications are huge for the homeowner or homebuyer left shivering in the dark by the inaccuracy. Enter Ralph Bouwmeester.
Mr. Bouwmeester is a Toronto-area civil engineer who created a unique solar computer model, a kind of hyper-sundial that accurately determines how much sunlight a building will get as well as where it will cast shade. The model is based on a series of astronomical formulas. For any position anywhere in the world, on any given date, it can calculate the position of the sun in terms of azimuth, the direction in relationship to true north and altitude, which refers to the height above an observer's horizon. To generate sun position data, basic input is required: dates, times and the observer's location expressed in latitude and longitude. Mr. Bouwmeester developed the basic program in 1982, making gradual improvements and refining the software for personal computer use in 1991. He has used the program on development projects since 1987.
The model can be used at the micro level for individual units and homes, as well as for large developments. Builders, developers, architects, municipalities, homeowners and ratepayers groups are lining up for Mr. Bouwmeester, who has saved many neighbour-hoods and properties from being eclipsed. His model is so effective he is in demand across North America,
HE HAS EVEN
THE BEST SPOT
FOR A BACKYARD POOL
having recently done sun-positioning analyses for office towers, high rises and single dwellings in California, Florida and New York City. The building and development boom in Toronto has revved his business into overdrive. While he has not consulted homebuyers directly as of yet, there is no doubt his services could be of value to someone who wants to make sure they are not getting a shady deal. He can tell prospective purchasers how much sunlight a property will get - and where it will fall - before they buy.
"I've been an amateur astronomer ever since I was a kid," says Mr. Bouwmeester, who became obsessed with sundials back in the early 1980's. "I wanted my model to take into account the fact that the Earth has an elliptical, not circular, orbit around the sun. Sundials, and the method many architects have used to determine sunshine at any given time of day, are based on latitude. But within each latitude the sun's position can change somewhat every 10 or 15 kilometres."
Mr. Bouwmeester got an opportunity to beta-test his model on a single-family infill project in Durham Region. A neighbour went to the Ontario Municipal Board, concerned that the new house would overshadow their property. Prior to the issuance of a permit, Mr. Bouwmeester was called in to do a sun-position analysis. There was good news all around. His survey concluded the shadow impact would be minimal and the house went up as planned.
His first high-rise project was the Oasis condominium in Don Mills. Another project in Scarborough, the St. Paul L'amoreaux retirement home at Warden and Finch Avenues, had Mr. Bouwmeester determining whether a new development next door would reduce the sun access of specific individual units. This led to minimal structural changes to the new building. In another situation, the owner of a downtown high rise wanted to transform its mechanical penthouse, which housed the building's electrical and utilities systems, by making some adjustments that would accommodate extra rental units. Would this affect sunlight on adjacent properties? Mr. Bouwmeester confirmed it would not.
Sometimes, his work has nothing to do with preventing disputes between neighbours. For a home in Fort Lauderdale, Fla., Mr. Bouwmeester was brought in to figure out how to position the swimming pool for maximum exposure to sunlight. He has even supplied evidence in court to support the claim of a defendant in a traffic accident case who maintained he had been blinded by the sun.
Mr. Bouwmeester is currently consulting on several proposed high-rise condominium projects, one in the Yonge Street and Eglinton Avenue area, another at Yonge near Summerhill Avenue, and on a plan to develop 13 high-rise condos on a large parcel of vacant land in Mississauga. He is also advising on a site intensification project - the development of two new residential high-rise buildings on a site with three existing high-rises in the Bayview and Steeles Avenues area.
"Certainly, some architects stick with their own analyses," says Mr. Bouwmeester. "However, the ones I deal with appreciate the fact that they can concentrate on what they do best, that is, design the building. They prefer to leave the sun/shade analysis to someone else who can take responsibility for that component of the project."
That said, developments continue to be built in the Toronto area without accurate shadow-impact studies. Not far from where Mr. Bouwmeester lives in Barrie, Ont., a new high rise was built on the waterfront where it looms over a marina, casting it in shade for most of the day. "I wish they'd called me," he says.
Article re-printed from "National Post" September 22, 2001 "National Post" is hereby acknowledged for the content.
ahead, croon along with Dino on that '50s station you're listening to in the car
remember, when the sun hits your eye like a big-a pizza pie, that it's not
amore, but sun glare.
glare, of course, can be a driving hazard around the calendar, but is especially
perilous in the fall. Today's installment of You Ask/We Tell explains why this
is so and what you can do about it.
the sun falls lower and lower on the horizon, sun glare becomes an issue simply
because sunrise and sunset suddenly coincide with the heaviest commuting hours,"
said Paul Walker, senior meteorologist at AccuWeather in State College,
do the astronomical math: The sun rose in these parts at 5:28 and set at 8:38 on
June 21, the longest day of the year, and it will rise at 8:20 and set at 5:20
on Dec. 21, the shortest day.
you conclude that this drive-time trick repeats in reverse in the spring, you're
right. But the fall still holds the edge in the sun-glare sweepstakes because it
often adds fog to the mix.
"There's a lot more fog in the fall,'' said Walker.
"Water temperatures are at their peak, nights are longer, winds are
best strategies for navigating this seasonal obstacle course are common-sense
ones, since, as Sgt. Tom Ferritto at Troop T in Albany puts it, "You can't not
go to work because of the angle for the sun."
Common sense is keeping the windshield spotless, inside
and out; keeping sunglasses — polarized, please — handy, and keeping the
dashboard and visors free of clutter.
"Make a habit of turning on your headlights when you
leave the house in the morning, too," said Sgt. Scott Mohl at Troop F in
Middletown. "Headlights, even hazard lights, will make your car more
Common sense is not buffing the dashboard to a blinding
big no-no is using a product like Armor All," said Ralph Bouwmeester, a civil
engineer and sun position expert in Barrie, Ontario. "You want a little
(Actually, Bouwmeester, who has reconstructed sun
position for accident and crime scenes, thinks the highway would be a better
place if dashboards were covered in black felt.)
none of this common sense compensates for failing to be aware of your
surroundings and alert to sudden changes.
"Many drivers don't anticipate well," Bouwmeester said.
"They should be looking ahead, to see where the shadow lines are."
Commuters are most vulnerable to accidents when they're
changing direction, not when they're driving straight into the sun. Negotiating
a curve or making a left turn brings into play a new set of sun and shadow
angles with the potential to obscure other cars or pedestrians, as well as
pavement markings and traffic signals.
don't forget," said Bouwmeester, "when you're driving away from the sun, that
the glare can wash out the brake lights of the car ahead of you."
Article re-printed from the "The Times Herald-Record", Middletown NY Oct 10, 2011
The early morning sun during the
equinox season can create a glare that has the potential to make rush hour even
more dangerous than usual.
Commuters are being blinded by the light. The Earth’s
orbit around the sun and the compass-points layout of the Valley’s road system
combine during the fall and spring equinox seasons to make rush hour even more
dangerous than usual.
People who drive east from their homes to their
jobs now are challenged twice daily to make out traffic signals, signs,
pedestrians and other vehicles against a backdrop of dazzling
The results can be fatal.
Last week, in a span of less
than 14 hours, there were two collisions in Mesa in which a driver looking into
the sun ran a red light. On Friday evening, the victim was a 14-year-old boy
walking home from football practice; the next morning at a different
intersection, a 51-year-old Gilbert man died when his vehicle was struck by a
Authorities blame the drivers, rather than the sun. But experts
know glare can be a factor.
"In Arizona the sun is very bright, and if
you’re not paying attention you can miss somebody because of it," said Paul
Hallums, president and CEO of the National Traffic Safety Institute in Tucson.
"It does interfere here substantially more than in other cities."
is exactly how much of a factor the sun is in crashes.
"It makes perfect
common sense," said Linda Gorman, spokeswoman for Mesa’s transportation
division. "But we just can’t prove it."
At least one expert who has
studied the sun’s effects knows what Valley motorists face every September and
March. Ralph Bouwmeester has made a
business of advising builders where to place sun decks, windows and gardens. He
also helps attorneys defend drivers who claim they were temporarily blinded by
Angela Cruz ran the red light on Longmore, striking Sean Casey as
he walked across Baseline Road around 5:30 p.m. Friday.
Bouwmeester’s computer re-creation places the sun within
7 degrees of straight ahead and 10 degrees up from the horizon. Translated to a
2-foot distance from Cruz’s eyes to the windshield of her Chevrolet Caprice, the
sun was slightly less than 3 inches to left of straight ahead and 4 1 /2 inches
up from the road.
conditions were even worse at 7 a.m. Saturday when Antonio Hernandez ran a red
light at Val Vista Drive on the eastbound off-ramp of U.S. 60. Hernandez was
looking at a sun that was 6 degrees to the right of center and 8 degrees up from
the horizon. He hit three vehicles, killing Lawrence Brabeck.
Some advice: Motorists aren’t helpless against the sun’s
powerful rays. Police offer these tips:
Slow down. If you can’t see well, give yourself more time to react.
Don’t drive with a dirty, cracked or pitted windshield.
sunglasses. The more protection for your eyes, the better.
• Keep your
sun visor clear of excess objects. "A lot of people put a lot of stuff up in
their visors," said Arizona Department of Public Safety Sgt. Kevin Jex. "So,
when they deploy the visor, they’re distracted by a bunch of papers falling in
Seeing through the glare
What is an
As we move toward fall the nights have grown longer and the days
shorter. At the equinox, the day and night are equally 12 hours long.
it affects the Valley:
Valley roads are built on a grid system that aligns directly north/south and
2 Because the sun is aligned with the equator during the
equinox it rises in line with eastern roads and sets in line with roads in the
3 The atmosphere acts as a magnifying glass on the light hitting
the Earth. The sun appears largest at sunrise and sunset because it is traveling
though the largest distance of atmosphere.
SOURCE: Montana State University; Tribune research Andrew
'The sun was in my eyes' is not an excuse, police say
By TOM ALEX - Des Moines Register
In your eyes: That
early-morning and late-afternoon sun can be blinding. Wear sunglasses and
use your visor, police advise.
Turn a corner
and it blinds you. Top a hill and it's worse.
Ignore precautions and it
could kill you.
This is the time of year when the sun's glare is
particularly dangerous for drivers and pedestrians. (See
"For two or
three weeks before and after September 4 and April 6, the early-morning and
late-afternoon sun is lining up closely with Iowa's east-west streets," said
Ralph Bouwmeester, a Canadian safety consultant and recognized expert on sun,
shadows and the optical tricks they play on motorists.
Des Moines lawyer
Sam Waters is also an expert on road glare. He learned the hard way.
accident occurred December 26, 1999," he said, describing a sunny Sunday morning
walk in Beaverdale with his wife, Elizabeth.
A driver, blinded by the
sun, struck the couple.
"I flew onto the hood and did a somersault in the
air and ended up 35 feet away," Waters said. "My wife hit the windshield, but
didn't go very far."
Both had knee surgery and have since
Theirs was far from an isolated incident:
• Sept. 9,
2003: Authorities said glare might have been a factor in a crash north of Des
Moines that killed a Pleasant Hill man. • Aug. 27, 2003: Two people on a
motorcycle died on the city's east side in a collision with an oncoming van
whose driver blamed early-morning glare. • Sept. 15, 2000: A 13-year-old boy
was struck by a car but escaped serious injury on his way to school. The driver
said the sun made it impossible to see the teen. • Sept. 15, 1999: A truck
loaded with jet fuel veered off Interstate Highway 80 west of Des Moines. The
driver blamed the sun. • Sept. 10, 1997: Authorities blamed a blinding
rush-hour sun for two traffic accidents that injured an 11-year-old girl and the
police officer sent to investigate. • Sept. 16, 1993 : The sun was listed on
reports as a contributing factor in several accidents, including a
car-pedestrian accident that killed a Windsor Heights woman.
Thousands of accidents each year are blamed on road
glare. The National Highway Traffic Safety Administration attributed 168 deaths
to blinded drivers in 2002, the lowest total in four years.
is the autumnal equinox. The 23-degree tilt of Earth's axis places the sun on
the horizon for eastbound traffic during morning rush hour. The tilt is what
creates the seasons.
It also can create highway havoc.
insurance company sponsored a study a few years ago that attributed this to
driver fatigue resulting from the affect of the time change on the body clock,"
Bouwmeester said. "I would suggest that the cause may be linked to the fact that
the sun appears lower on one's drive home from work."
The problem is at
its worst the first hour after sunrise and the last hour before
"The sun was in my eyes" is no excuse for an accident, said Des
Moines Police Sgt. David Coy.
"Wear sunglasses, use your visor, delay
your trip until the sun is higher in the sky," he said.
That means put
down the cell phone and leave the radio dial where it is.
"Get all of
that out of the way before you start driving, because you may need one hand to
block the sun while you keep the other on the wheel," Coy said.
Article re-printed from the "Des Moines Register" September 16, 2004
The "Des Moines Register" is hereby acknowledged for the content.
This time of
year (ed. spring and fall equinoxes), the sun is rising directly to the east, and setting directly to the west.
As a result, motorists who use east-west roads such as Interstate 20, Interstate
30 and Texas 183 are probably doing a lot of squinting.
Sun glare may
be more of a factor in motor vehicle crashes than many people realize. It's a
problem that becomes more pronounced in the fall and winter, when the days are
shorter and the sun is setting during afternoon drive time.
departments keep close track of other conditions -- rain, ice, snow and even
darkness -- when filling out accident reports. But few keep track of
Bouwmeester, a civil engineer who lives in Barrie, Ontario, says he has
testified in dozens of court cases in which glare was cited as a factor in a
who says he has had a lifelong passion for sundials, has carved an interesting
developed a computer program that precisely tracks the path of the sun and its
rays in just about any situation.
call upon his expertise to re-create light conditions in traffic
program, Bouwmeester can build a computer model that takes into account weather
conditions, smog and shadows cast by trees and buildings.
Glare seems to
bother motorists more in late March, late September and when communities change
to or from daylight savings time, he says.
disproportionate number of accidents occur after the switch back to standard
time in the fall," he says. "There was an insurance company that did a study
about it, and they were attributing it to the body clock and people being tired.
Personally, I'm wondering if it's better attributed to the sun's changing
position on the drive home. You come around a corner at 60 mph every day for two
weeks without a problem. Now, all of a sudden, you're coming out of work with an
hour's difference. All of a sudden, there's the sun and you weren't expecting
doesn't have to be shining directly into your windshield to cause problems,
"It can bounce
off other cars, the asphalt on the road and even the dashboard," he
administration has proposed that the amount of federal money spent on highway
safety be more than doubled to $7.5 billion over the next six years.
decades, exhaustive research has been conducted on how roads can be engineered
But only in
recent years have researchers focused more of their attention on driver
behaviors and distractions.
that in the next few years more light will be shed on the dangers of sun
Article re-printed from the "Dallas Fort Worth Star Telegram" September 15, 2003
The "Star Telegram" is hereby acknowledged for the content.