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Portland Bureau of Transportation

Phone: 503-823-5185

Fax: 503-823-7576

1120 SW Fifth Ave, Suite 800, Portland, OR 97204

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Bridlemile Elementary School

School Safety Project
Final Evaluation
The Traffic Calming Program (TCP) undertook a School Safety Project (SSP) in the Fall of 1994 on SW 47th Drive, adjacent to Bridlemile Elementary School.
The goal of a SSP project is to enhance the safety of the younger pedestrians associated with the elementary school by reducing the 85th percentile speed closer to the posted speed limit. Speed bumps are the only device considered for streets like SW 47th Drive, which is classified as a Local Service Street, is not a transit or primary fire response route and has vehicle volumes between 400 and 1700 vehicles per day. Speed bumps have proven to be the most effective tools to reduce vehicle speed without impacting access. It is not an intended goal to reduce traffic volume on low-volume Local Service Streets.
SW 47 Drive is a short street in a suburban-rural setting serving as a primary entry to a single-family residential neighborhood on its North side and Hamilton Park and Bridlemile Elementary School to the South. There are sidewalks along the frontage of the school. The school's frontage comprises approximately half of the south side of SW 47th Drive with Hamilton Park fronting the remainder of the south side. A single cross-walk is provided at SW 48th Way, otherwise, there are no other pedestrian accommodations.
Open House
All residents along the project streets were invited to an open house February 7, 1995 in order to review and comment on the proposed bump installation. Seven households were represented at the open house, as well as the school principal. The majority of those who attended expressed approval for the proposed project. Two households disapproved of the bumps as excessive. There is no petition or ballot requirement for School Safety Projects as they are a City Council mandated activity.
The project speed bumps were constructed in April of 1995 by the Bureau of Maintenance.
As the graph shows, vehicle speeds, previously spread between 23 and 31 mph, have been concentrated into the range of 20 to 28 mph. The 85th percentile vehicle speed before the project was 27-35 mph. After bump construction the average 85th percentile speed measured was 27 mph. The 85th percentile speed ranged from a low of 24 mph at a bump to a high of 30 mph.
Traffic Volumes measured after bump construction showed no significant change from the pre-bump volumes of 800-1000 vehicles per day (vpd). No adjacent streets were identified as unwanted diversion routes.
Traffic calming on SW 47th Drive has been successful and school pedestrian safety has been enhanced.