Ayres Knowledge Center Using Bike Boxes to Increase Visibility and Safety | Page 5

About 77% of motorists stopped at the appropriate
position before the installation (at the stop bar before
the pedestrian crosswalk), while 73% stopped at the
appropriate position after the installation (at the stop bar
protecting the bike box), according to the Portland report.
This nearly identical compliance rate came despite the fact
that the bike box sets the stop line back significantly from
the intersection.
Motorists surveyed indicated an understanding of the bike
boxes of 86% or better.
In addition to reducing conflicts, the Portland bike
boxes appeared to improve bicyclist behavior in some
ways. “Cyclist encroachment in the crosswalk decreased
significantly after the installation of the bike boxes,
dropping from 41% to 25% of cyclists arriving on a red
signal,” the report states.
As for green bike boxes compared with non-colored bike
boxes, the green boxes reduced motorist encroachment
in the bike area and encouraged bicyclists to position
themselves in front of the vehicle stop line – more so than
without the colored pavement, according to the study.
No significant difference in conflict frequency was noted
between color and no-color bike boxes, but nearly 90%
of motorists voiced a preference for green. As for why
green has risen to prominence as the color for bike boxes,
durability and nighttime visibility are two of the primary
reasons.
Another community that implemented and then studied
bike boxes is Austin, Texas.
This study looked at the behavior of drivers and bicyclists
at two intersections where new bike boxes were installed
for the intended benefit of bike traffic that largely
continues straight through the intersections of Speedway
at 38th Street and Shoal Creek Boulevard at Anderson
Lane. Like the Portland study, this one looked at bike boxes
that did not accommodate left turns by bikes. As part of
this study, the bike boxes first were installed and studied
without color, and then color was added, and further
observations were made for comparison.
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