Over half Sellwood commuter traffic involves Clackamas County; the traffic leads to cut-thru driving

DAVID F. ASHTON - PBOT Traffic Design Section Manger Janie Jeffrey explained some of the data collected used to create the matrix of recommendations. Traffic persistently clogs S.E. Tacoma Street from the Sellwood Bridge out past the McLoughlin Boulevard overpass during the morning and afternoon rush hours – and for quite some time, the SMILE Transportation Committee and the Portland Bureau of Transportation (PBOT) have been looking for a solution.

At a meeting at SMILE Station a short time before Christmas, some 40 people interested in the topic packed the room to hear about possible solutions for the resulting cut-through traffic that spills out through neighborhood side streets.

"The goal of the meeting is to fine-tune alternatives for improving congestion issues around the Tacoma Street Corridor," explained SMILE Transportation Committee Chair Scott Kelly as the meeting began. "Tonight, PBOT will present alternatives they're considering, based on feedback from our previous meeting. They will then fine-tune them even more, to come up with a plan to implement improvements."

Stepping up was PBOT Project Manager Rich Newlands: "We continue to work with a team of folks – traffic engineers, primarily – to figure out this issue that impacts Sellwood-area neighborhood livability – the impact of traffic congestion, along both main and side streets, leading to and from the Sellwood Bridge."

PBOT's involvement began, Newlands recalled, shortly after the new Sellwood Bridge opened. "And, since then, we have been hearing complaints about growing cut-through traffic issues. Early in the spring of 2017, we decided to actively study the issue, and start a dialogue with the community about what could be done to address it.

"The takeaway is, we're looking to see if there are ways that we can smooth traffic flow on the Sellwood Bridge, and on Tacoma Street, to reduce the tempting incentive to use alternative routes on side streets – in other words, to discourage non-local, cut-through traffic."

Although a lot of local drivers do use the Sellwood Bridge, past studies have consistently shown that the majority of the weekday commuters using the bridge are coming from, or are enroute to, Clackamas County.

Newlands remarked that the extensive data collection PBOT undertook last summer shows that traffic volumes on side streets, primarily south of Tacoma Street and west of 17th Avenue – as well as north of Tacoma Street – are, indeed, above average for what would be expected for locally-generated traffic.

"The patterns of traffic, looking east to west, also clearly indicates that there is a cut-through traffic problem," Newlands conceded. "It is city policy to design and manage roadways so that drivers stay on arterial networks for arterial trips. The trips over the Sellwood Bridge are not all local trips; and we have reason to believe that a lot of the traffic is coming from Clackamas County."

There are few traffic-control strategies and methods that are likely to provide a lot of "bang for the buck" for easing the congestion, Newlands remarked. "We're looking for ways of discouraging the bad behavior of cutting through side streets, and at the same time, keeping an open mind to offer strategies that offer both 'carrots and sticks'."

As the meeting got underway, PBOT Traffic Design Section Manger Janie Jeffrey joined Newlands, and both together gave a presentation.

The PBOT representatives made it clear that they were not presenting any "preferred alternatives" at the meeting, but instead were illustrating a wide variety of options – and all of these options do also have trade-offs.

"It is a question of which of the alternatives, except for extraordinarily expensive ones, will – in and of themselves – contribute significantly toward solving the problem," Newlands told the group.

Jeffrey walked the group through the presentation providing about a dozen main categories of options, each with numerous permutations, including:

· Signal timing adjustments at the west end of the bridge

· Convert the bridge to reversible travel lanes

· Replace the S.E. 6th and Tacoma traffic signal with a pedestrian hybrid beacon, such as the one now at Tacoma Street at 19th Avenue

· Access restrictions, using traffic diversion

· Metering traffic flow on 17th Avenue to potentially reduce the amount of outside commuter traffic entering neighborhood from the south on 17th Avenue. Bonus: This could improve safety at the Springwater Trail crossing; but it could pose potential for unacceptable unintended consequences

· Improve Umatilla Street as a Greenway, with speed bumps and a 20 mph speed limit, "Sharrow" pavement markings, and possible diversion

· Add a stronger 6th Avenue diverter, south of Tacoma Street

To view a PDF document of the entire matrix, go online --

The next steps in this long process include adopting a three-tier "Implementation Strategy", then addressing feasibility and desirability issues, then designing construction and assessment.

To learn more about the SMILE Transportation Committee, go to their webpage:

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