Pedestrian Safety Guide and Countermeasure Selection System

 

Case Study No. 87

Nickerson Street Road Diet

Seattle, Washington

Prepared by Ann McGrane, University of North Carolina Highway Safety Research Center. Information provided by Brian Dougherty, Seattle Department of Transportation, Seattle, Washington.

Problem

Nickerson Street in Seattle, WA, was a difficult roadway for pedestrians to cross because it had four travel lanes and few pedestrian crossings.

Background

Nickerson Street before the lane rechannelization.

In 2008, the Seattle Department of Transportation removed three crosswalks on Nickerson Street because the crosswalks no longer complied with the guidelines for when to use uncontrolled marked crosswalks. The City promised neighborhood residents that it would look into ways to improve pedestrian safety along the roadway in the future.

Nickerson Street also had a low rate of driver compliance with the speed limit. The speed limit on the roadway was 30 mi/h, but the 85th percentile speeds were 40.6 mi/h westbound and 44.0 mi/h eastbound. The difference between a vehicle going 30 mi/h and 40 mi/h could be a matter of life or death in a vehicle-pedestrian crash.

Solution

Nickerson Street after the lane rechannelization.

In 2010, the Department of Transportation decided to reconfigure Nickerson Street between 13th Avenue West and Florentia Street by reducing the number of lanes from four to three. This rechannelization, or "road diet," consisted of one travel lane in each direction, a two-way left turn lane, and bicycle facilities. A bike lane was installed going uphill, and sharrows were added to the downhill travel lane. By reducing the number of travel lanes, it was safe to reintroduce uncontrolled marked crosswalks to the roadway. Marked crosswalks and median islands were installed at Dravus Street and 11th Avenue West. Having one travel lane in each direction made pedestrians safer from shielding crashes in which the vehicle in the outer travel lane yielded to the pedestrian while the vehicle in the inner travel lane did not.

The cost of the rechannelization was $241,973, and the project was funded through the "Bridging the Gap" transportation levy that was approved by voters in November 2006.

Results

Pedestrian refuge islands provided a safe space for pedestrians to assess oncoming traffic.

The rechannelization of Nickerson Street led to dramatic reductions in speed. In February 2011, data were collected that showed the 85th percentile speeds as 33.1 mi/h westbound and 33.3 mi/h eastbound. Those speeds amounted to 18 and 24 percent reductions in the 85th percentile speed, respectively. The number of vehicles traveling the roadway remained fairly constant, with about 18,500 vehicles per weekday prior to the rechannelization and 18,300 vehicles per weekday after the rechannelization.

Seattle continues to use rechannelizations as a way to improve roads for all modes of transportation. As of March 2012, 36 road rechannelizations had occurred in the City.

Contact

Brian Dougherty
Seattle Department of Transportation
Traffic Management Division
700 Fifth Avenue, Suite 3700
PO Box 34996
Seattle, WA 98124-4996
Phone: (206) 684-5124

References