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The City of Portland, Oregon

Portland Bureau of Transportation

Phone: 503-823-5185

Fax: 503-823-7576

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

More Contact Info

Left turn calming

Left turn calming uses modular speed bumps, plastic curbing, flexible posts, and thermoplastic to slow turning speeds and improve left-turning drivers’ view of the crosswalk.

How left turn calming supports safety:

  • Safer turning speeds
  • Prevent corner cutting
  • Turning vehicles more directly face crosswalks, improving drivers' view of pedestrians

Left turns present special hazards to vulnerable road users. One of the most common crash types on High Crash Network streets in Portland occurs when a person in a crosswalk is hit by a left-turning driver. Left-turning drivers can also collide with people biking straight through an intersection. Left turn calming may help prevent these crashes. 

Portland is piloting left turn calming starting in summer 2019 and continuing into 2020. Evaluation results will inform long-term use. Preliminary results from New York City indicate that left-turn calming may be an effective safety treatment.


Treatment location criteria

  • 1-way to 2-way or 2-way to 2-way streets
  • Appropriate geometry
  • Any number of travel lanes
  • Permissive lefts allowed (no left turn signal)
  • Traffic signal
  • Located on High Crash Network street, High Crash Network Intersection for people walking or biking, or history of left turn crashes
Pilot treatment locations (subject to change) Details Status
E Burnside Street & 55th Avenue    
E Burnside & 60th Avenue    
SE Stark Street & 99th Avenue South leg only, wedge on NE corner  
SE Stark Street & 117th Avenue    
SE 122nd Avenue & Market Street   Installed 6/10/2019 
SE 122nd Avenue & Harold Street    
SE César E. Chávez & Holgate boulevards South leg only  
SE Holgate Boulevard & 104th Avenue    
SE 106th Avenue & Washington Street North leg only  
SE Stark Street & 139th Avenue    
SE Division Street & 174th Avenue   Installed 5/17/2019
SE Foster Road & 92nd Avenue South leg only  
SE Foster Road & 110th/111th avenues   Installed 5/16/2019
N Killingsworth & Williams streets West leg only  
NE Martin Luther King Jr. & Lloyd boulevards Wedge only, NE corner  
SE 7th Avenue & Hawthorne Boulevard Wedge only (posts), SW corner Installed 4/27/2019
SE Hawthorne Boulevard & 30th Avenue    
SW Market Street & 4th Avenue Wedge only, SE corner  
SW Columbia Street & 4th Avenue Wedge only, NW corner  
W Burnside Street & 3rd Avenue East leg only, wedge on SW corner  
W Burnside Street & 11th Avenue East leg only  
NW Couch Street & 10th Avenue West leg only  
SW Alder Street & 13th Avenue Wedge only, SW corner  
SW Capitol Highway & Sunset Boulevard    
SW Beaverton-Hillsdale Highway & Shattuck Road    
N Interstate Avenue & Mississippi Street Wedge only, SE corner  
SE Division Street / 20th Avenue / Ladd Avenue    
SE Belmont Street & 30th Avenue    
SE Stark Street & 102nd Avenue Wedge only, SE corner  

Treatment components

Left turn calming includes a hardened centerline and/or a “wedge” at intersection corners. Wedges are similar to curb extensions, but are located outside of crosswalks and are designed to be driven over.

Portland is testing two types of hardened centerlines: one using a combination of plastic curbing, posts, and rubber speed bumps, and another design that uses only rubber speed bumps.

Most wedges use only rubber speed bumps and thermoplastic, and may be used to slow left- or right-turning drivers.


Evaluation

The pilot will be judged successful if any of the treatment variations result in:

  • Slower turning speeds,
  • Less corner cutting, and
  • Reasonable maintenance costs

Post-pilot

If the pilot is successful, PBOT will determine whether pilot treatment locations become program assets or maintenance assets and will consider expanding treatment locations.

Once crash data is available, PBOT will re-evaluate the treatment locations to inform long-term plans.

Questions about the pilot: Email Matt Kelly or call 503-823-5831

6/10/2019