Double Warning Blank Out Signs Help Congestion in Phoenix School Zone

Posted by Mike McKay on Dec 28, 2016 11:26:05 PM
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The  Traffic Deadlock Dilemma

school entry mobility no right turn 3.jpgLooking to address the traffic deadlock dilemma that plagues many urban American experiences, the City of Phoenix has deployed a double warning system in the drop zone of a local school. This area is prone to high volume vehicular congestion, especially during morning drop-off hours, with a left turn pocket at the school ground's entrance that clashes with a right turn lane from the other direction. These opposing lanes are often at odds, with drivers from both directions feverishly attempting to enter the drop zone area first. 

As the left turn traffic approaches, the traffic from the opposing direction capitalizes on the signal lag and flow, employing a quick right turn. The traffic congestion is then further hampered by the wide design of the high school's entryway, which quickly narrows. This tapering of the primary roadway results in a chaotic vehicle overflow that stifles through traffic to a stop from 45 MPH. 

The Safe School Solution

school entry mobility no right turn 1.jpgThe viable solution to this drop zone congestion was to remove the free right turn, unless the signal was green, allowing all the left turn traffic to enter during their designated signal phase. To implement this traffic control strategy, the City of Phoenix deployed two SESA 24 inch, LED NO RIGHT TURN symbol signs. The first sign, set in advance of the right turn traffic, was timed to activate in tandem with the signal change to green for opposing traffic.

This robust, easily observable sign set the stage for a second sign that is located on the opposite side of the intersection. Another concern the City of Phoenix had was protecting the only pedestrian crossing into the school grounds, which was affected by the potentially frantic, time-consumed right lane drivers attempting to be the first enter. The second SESA LED Blank Out Sign further reinforced the new traffic control system and protected crossing pedestrians. 

SESA 'NO RIGHT TURN' Blank Out Signs

For the City of Phoenix project, our SESA NO RIGHT TURN symbol signs were equipped with a light sensor to seamlessly adjust to morning light conditions and with no polycarbonate face to provide better than average contrast for the intense desert sun. The signs pictured demonstrate a head on position to the eastern morning sun. Additionally, SESA supplied full hoods to create a shading effect as drivers proceed westerly into the sun during afternoon pick-up hours. Both of these Blank Out Signs are maximized with complete 30 degree viewing angles, made possible by the calculation of a SESA microprocessor that offers the appropriate lighting for the often blinding, sunset conditions in the Valley of the Sun. Changes over the years in LED efficiency has eliminated the printed computer board with this SESA design. The City of Phoenix can now replace LED’s singularly, reducing maintenance costs to cents rather than hundreds of dollars. In addition, the advanced brightness ability in this new design allows for less LED's, driving down costs and providing a greater value-to-reliability ratio. 

SES America is an ITS-only manufacturer of messaging solutions for American streets and highways since 1986. Long considered the innovation leader, SES America is a solutions first, service focused supplier of the most advanced, energy efficient designs in USA and North America.


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Topics: Mobility, Blank Out Signs, Traffic Control