Why Blue?
The City of Portland selected the use of blue for the first phase of
testing based on several factors.
- Conflicting meanings for other colors
Throughout the American transportation system, yellow signifies
opposing traffic flow. Red and green both have very distinct meanings
-- red signifies no entry and green means go.
- Color blindness
Many people have a limited ability to differentiate colors. In
particular, many color blind or impaired individuals find it difficult
to see red and other earth tones, as well as green. In low light and
wet conditions, such as rain and fog, blue shows up.
- Public support
Prior to the start of the project, Office of Transportation staff
presented the color options to dozens of local community groups,
including neighborhood and business associations, transportation
professionals, bicycle advisory committees in Oregon and Washington,
and bicycling and other interested community groups. We found that
blue was preferred because of the driving conditions common to
Portland.
- Evidence from Denmark and Montreal
A recent study in Denmark found blue to be the most
visually powerful type of marking, and that at intersections marked in
blue, the number of bicycle accidents decreased significantly by 38%
and the number of fatalities and serious injuries were reduced by 71%.
(Source: "Junctions and Cyclists" a paper presented at the
Velo-Cité 1997 Conference). In addition, a 1996 study in
Montreal, Quebec--the only other city in North America to use colored
pavement--found the use of blue at five intersections resulted in a
small but significant decrease in the number of conflicts.
Because this is a test, other colors may be used in the future.
Are they slippery?
No. We investigated many different types of materials with the issue of
slickness in mind. The paint we have used is no more slippery than normal
asphalt.
How long will the painted area last?
Unfortunately, paint does not last long. With the volume of motor
vehicle traffic turning across these intersections, the paint will likely
be worn off in a few months. We are planning to repaint the areas in the
Spring and Summer in order to ensure they are well marked during the test
period.
Plastic materials are more expensive but would last longer. However, we
are still researching the use of these plastics, with several concerns.
- Will they be slippery?
- Will they bond well to existing asphalt?
- Will they last long enough to justify the additional cost?
Why do you think it will work?
Much evidence shows that the use of colored pavement helps improve
safety.
- A recent Swedish study found the use of colored markings increased
safety per bicyclist by 20%.
- Denmark found the use of blue markings reduced bike-motor vehicle
collisions by 38% and fatalities and serious injuries by 71%.
- Studies in England and Scotland also showed colored markings to be
effective at reducing conflicts.
- Red bike lane colorings at crossings are standard practice in Dutch
cities, where the percent of trips made by bicycle ranges from
20-to-60%.
- Colored bike lanes has become common practice in many German, French
and Swiss cities as well.
- A 1996 study in Montreal, Quebec found the use of blue at five
intersections resulted in a small but significant decrease in the
number of conflicts.
If they've proven to be useful in other cities, why do we have to test
them here?
There are standards governing the use of traffic control markings like
signs, stripes, and signals, so that all cities throughout the U.S. have
as uniform traffic controls as possible. These standards are set forth in
a document called the Manual on Uniform Traffic Control Devices (MUTCD).
The MUTCD does not provide for the use of colored markings to delineate
bike lanes or conflict areas. We are testing the use of colors in bike
lane conflict areas through our partnership with the University of North
Carolina Highway Safety Research Center and the Federal Highway
Administration.
In addition, although these markings have been used extensively in
European cities, they have never been used in the U.S. In comparison to
European cities, much is different: our driving habits, the number of
cyclists, the configuration of streets and intersections, the common use
of pavement markings rather than signs. Because of these differences, we
believe it is important to verify that colored markings will work here
before adopting this technique. If the colored pavement markings prove to
be effective, we will petition the appropriate standards-setting
committees for their inclusion in the national and state standards.
Doesn't the cost of the project seem high?
The project's $89,000 budget is intended to pay for a comprehensive
analysis of the utility of this technique so that Portland and cities
throughout the U.S. can, hopefully, add it to the toolkit of bicycle and
motorist safety options. In addition, it will pay for the installation of
markings and signs at about a dozen locations.
In comparison, the average direct costs (e.g., property damage, medical
bills, time loss) of an injury accident is $54,400. If this $89,000
project results in preventing just two injury accidents it will be cost
effective. If the technique is found to be effective and is then used
throughout the City, the payback would be enormous.
How do I get other intersections to be painted blue?
At this time, we still consider the use of blue paint to be
experimental. Once the test phase is complete, we will have determined
whether blue markings are useful or not. If they prove to be useful, we
will consider additional intersections for modifications. At this time,
you can let us know which intersections you would like us to consider for
the future by sending e-mail to Portland
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