Synthesis of Safety for Traffic Operations - Transports Canada

Pedestrian Safety
The researchers correctly identify the following limitations of the above analysis:
• The after study was completed within four weeks of sign installation; longer-term
effects of these signs are not known; and
• The sites were geographically focussed and transferability of these results to other
jurisdictions is unknown.
School Zone Traffic Control
Schrader (1999)
The City of Springfield, Illinois studied the effectiveness of five school zone traffic
control devices by measuring 85 th percentile speeds in a before-after analysis with a
comparison group (Schrader, 1999). Five treatment sites and one comparison site shared
the following characteristics:
• a 20 mph speed limit “on school days when children are present”;
• a collector road designation; and
• a high number of pedestrians.
The treatments are as follows:
• Treatment 1: A post-mounted flashing beacon was erected at the entrances to the
school zone, and the “on school days when children are present” text on the
school zone speed limit sign was replaced with “when flashing”.
• Treatment 2: The posts of the school zone speed limit signs were painted
lavender, and lavender transverse stripes were marked on the road. The spacing
between successive stripes decreased as one moves downstream.
• Treatment 3: Span wire mounted flashing beacons, and school zone speed limit
signs were erected at the entrances to the school zone, and the “on school days
when children are present” text was replaced with “when flashing”.
• Treatment 4: The school zone speed limit signs were replaced with internally
illuminated, fiber optic signs with the legend “School Speed Limit 20”. The signs
were illuminated during school hours.
• Treatment 5: The entrance to the school zone was supplemented with a pavement
marking reading “20” in 2.44 metre high lettering.
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