What areneighborhood greenways?
In Portland, our more than 90 miles of low-stress bike streets, known as neighborhood greenways, are critical to helping everyone get around Portland, whether they ride bicycles or not. They also form the backbone of the city’s Safe Routes to School network, providing places for people of all ages and abilities to bike.
Anyone who travels in Portland knows that traffic is increasing. While our population is expanding, our roadway space is not. In 2010 Portland’s population was 580,000; by 2035 it is expected to reach 860,000. Building enough roads for all these new residents to get around by driving simply isn’t feasible or desirable.
By investing in neighborhood greenways, Portland creates safe places for people to take trips by walking and bicycling. Research shows that family-friendly bikeways that feel safe and comfortable attract new riders. We know that travelling by bike doesn’t work for every person or every trip—but these safe, connected neighborhood greenways draw more people who can use bikes. That helps leave space on the roads for people who can’t use alternatives to driving.
The SE Lincoln-Harrison Neighborhood Greenway is one of the city’s oldest and one of six that PBOT identified as needing immediate attention due to the volume and speed of cars using it.
One of the most stressful parts of riding a bike on a shared roadway is when someone driving tries to pass you. For this reason, PBOT aims to design, build, and maintain neighborhood greenways with two numbers in mind: 1,000 vehicles per day (on average), and 50 vehicles per hour travelling at peak times of the day and in the direction most common at peak time. When neighborhood greenways meet these two conditions, a person bicycling is much less likely to be passed by a car.
To ensure this project met is goals, PBOT collected automobile speed and volume data at over 50 locations along the greenway and on surrounding neighborhood streets before the project was constructed. This data formed a baseline to compare speeds and volumes six months after PBOT completed construction. Links to this before-and-after data is included below, but it only represents a snapshot. PBOT is still constructing certain elements of the project and still collecting data. PBOT will publish a full report when all project elements are done.
How is the SE Lincoln-Harrison Neighborhood Greenway doingsince these changes went in?
Although PBOT has yet to install all speed bumps, the initial data demonstrates significant success. In several key locations, there are fewer total cars on the SE Lincoln-Harrison Neighborhood Greenway:
- SE Lincoln Street at SE 30th Avenue – 41% decrease in average daily traffic (ADT)
- SE Lincoln Street just east of SE 50th Avenue – 51% decrease in ADT
- SE Lincoln Street just west of SE 50th Avenue – 50% decrease in ADT
- SE Lincoln Street at SE 57th Avenue – 16% decrease in ADT
How are streets near the neighborhood greenway doing since these changes went in?
The intention of this project was not to push high levels of auto traffic to the side streets adjacent to the greenway. Ideally, traffic volume on adjacent local service streets will perform the same way as the greenway does—that is, volume not exceeding 1,000 cars per day or 50 cars per hour during peak times.
If a side street went from having traffic volumes under these thresholds before the project went in to traffic volume above these thresholds afterward, then PBOT has committed to providing further mitigation to offset these effects.
Our preliminary data shows that most of the side streets are still performing well, below these thresholds. However, PBOT sees the need to continue to monitor the following locations:
- SE 48th Avenue north of SE Division Street
- SE Harrison Street west of SE 49th Avenue
- SE 28th Place south of SE Harrison Street
- SE Market Street east of SE 30th Avenue
- SE 25th and 26th avenues north of SE Harrison Street
- SE Stephens Street east of SE 25th Avenue.
Common ways that PBOT mitigates the impact of higher traffic volume is by adjusting the placement of stop signs, adding speed bumps, modifying the primary greenway project, or applying diversion to a secondary street.
Please don't hesitate to contact Scott Cohen, Neighborhood Greenway coordinator, with questions or comments.