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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

Locations and status

Pilot treatment locations Details Status
E Burnside Street & 55th Avenue   Installed 6/18/2019
E Burnside Street & 60th Avenue   Pending installation
SE Stark Street & 99th Avenue South leg only, wedge on NE corner Installed 7/24/2019
SE Stark Street & 117th Avenue   Installed 10/4/2019
SE 122nd Avenue & Market Street   Installed 6/10/2019 
SE 122nd Avenue & Harold Street   Installed 8/24/2019
SE César E. Chávez & Holgate boulevards South leg only Pending installation
SE Holgate Boulevard & 104th Avenue   Installed 7/25/2019
SE 106th Avenue & Washington Street North leg only Installed 7/24/2019
SE Stark Street & 139th Avenue   Installed 10/7/2019
SE Division Street & 174th Avenue   Installed 5/17/2019
SE Foster Road & 92nd Avenue South leg only Pending installation
SE Foster Road & 110th/111th avenues   Installed 5/16/2019
N Portsmouth Avenue & Willamette Boulevard   Preparing work order
N Killingsworth & Williams streets West leg only Pending installation
NE 122nd Avenue & Fremont Street   Preparing work order
NE 67th Avenue & Glisan Street   Preparing work order
NE Martin Luther King Jr. Boulevard & Lloyd boulevards Wedge only, NE corner Pending installation
NE Martin Luther King Jr. Boulevard & Ainsworth Street   Preparing work order
NE Martin Luther King Jr. Boulevard & Dekum Street   Preparing work order
NE Weidler Street & 16th Avenue   Preparing work order
SE 7th Avenue & Hawthorne Boulevard Wedge only (posts), SW corner Installed 4/27/2019
SE Hawthorne Boulevard & 30th Avenue   Installed 7/20/2019
SE Flavel Street & 52nd Avenue   Preparing work order
SW Market Street & 4th Avenue Wedge only, SE corner Installed 9/27/2019
SW Columbia Street & 4th Avenue Wedge only, NW corner Installed 9/26/2019
W Burnside Street & 3rd Avenue East leg only, wedge on SW corner Installed 9/15/2019
W Burnside Street & 11th Avenue East leg only Installed 9/15/2019
W Burnside Street & 21st Avenue   Installed 9/15/2019
NW Couch Street & 10th Avenue West leg only Installed 9/15/2019
SW 10th Avenue & Jefferson Street Wedge only, SW corner Preparing work order
SW Alder Street & 13th Avenue Wedge only, SW corner Installed 6/29/2019
SW Capitol Highway & Sunset Boulevard   Installed 9/15/2019
SW Beaverton-Hillsdale Highway & Shattuck Road   Installed 4/2019
SW Beaverton-Hillsdale Highway & Dosch Road   Preparing work order
N Interstate Avenue & Mississippi Street Wedge only, SE corner Installed 7/15/2019
SE 96th Avenue & Main Street   Preparing work order
SE Division Street / 20th Avenue / Ladd Avenue   Pending installation
SE Belmont Street & 30th Avenue   Installed 7/20/2019
SE Stark Street & 102nd Avenue Wedge only, SE corner Installed 6/18/2019

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 can be driven over if necessary.

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. Where space allows, Portland installs an additional rubber speed bump "nose" that extends slightly into the intersection.

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

Hardened centerlines with noses can be seen below at East Burnside Street & 55th Avenue:


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

10/16/2019