Most Chelan intersections projected to fail summer traffic standard by 2050

CHELAN — Most intersections studied in Chelan are projected to fall below the city’s traffic standard during peak summer conditions by 2050, according to transportation modeling presented to the City Council and Planning Commission Sept. 8.

The projections are part of an update to the transportation element of Chelan’s comprehensive plan, which looks ahead to 2050 and is intended to identify projects, policies and funding strategies needed as the city and surrounding area grow.

Daniel Hendricks, senior project manager with Transpo Group, presented the findings alongside Public Works Director Jake Youngren. The city’s existing standard for vehicles is Level of Service D or better, a threshold that is not changing in the update.

Level of service grades road and intersection operations from A through F, with A representing little delay and F representing long delays and congestion. Intersection grades are based on average delay per vehicle.

What is changing is when Chelan evaluates whether it meets its standard. The updated plan focuses on peak summer conditions, when the city experiences substantially more traffic than during the rest of the year.

Traffic data presented by Transpo Group showed average weekday afternoon peak traffic at 1.29 times the annual average in June, 1.47 times the average in July and 1.44 times the average in August.

Under average conditions, most intersections analyzed are projected to continue meeting the city’s D-or-better standard through 2050, although several stop-controlled intersections along state routes would require improvements.

The summer forecast is considerably different.

“Many of these intersections currently operate okay during the summer conditions, but there are a couple in the downtown area that do operate with substantial delay today during summer conditions,” Hendricks said. “Once we incorporate future growth into this, a lot more of those issues are exacerbated.”

The city’s presentation showed most studied intersections falling below Level of Service D during summer conditions by 2050, with many projected at Level of Service F and others at E.

The projections are based on the Chelan-Douglas Transportation Council’s Chelan-Manson Travel Demand Model, which incorporates land-use plans for both the city and county. The underlying 2023-to-2050 forecast assumes annual household growth of 5.4% and job growth of 1.6% across the full model area, including Chelan, its urban growth area and portions of Chelan County.

That regional growth became one of the central issues during council discussion.

While Chelan can impose concurrency requirements on development within its jurisdiction, growth outside the city can also send additional traffic through Chelan intersections.

Community Development Director John Ajax used Manson as an example, noting that the city does not control development there even when resulting traffic contributes to congestion inside Chelan.

“If we’re at an F right now, we’re failing, that’s entirely on the city and that becomes a much bigger discussion on how do you fund or how would you ask constituents inside the city limits to pay for improvements to intersections that are being degraded by, for example, growth that’s happening in Manson,” Ajax said. “I mean, there’s a fairness question there.”

For development occurring inside Chelan, concurrency rules require enough transportation capacity to be available or funded before development can proceed. If a proposed development would cause an intersection operating at Level of Service D to fall to F and the developer cannot mitigate that impact, the development cannot be approved.

However, if an intersection is already failing, a new developer cannot be required to pay the entire cost of bringing it back to the city’s standard. The developer can only be required to address its proportionate impact.

That issue is reflected directly in the proposed transportation policies. One goal calls for growth to pay for growth and says existing residents and taxpayers should be protected from subsidizing transportation infrastructure whose primary purpose is serving new private development. Another calls for a regional planning approach across Chelan, Manson and the lower Lake Chelan basin using common standards, funding tools and permitting requirements.

Ajax said Chelan is working with Chelan County, the Washington State Department of Transportation and the Chelan-Douglas Transportation Council on those overlapping traffic issues.

The model includes future traffic forecasts extending through Manson, though officials said it does not provide intersection-by-intersection level-of-service analysis there.

Potential improvements are still being developed as part of the transportation element. Hendricks said the city is examining projects intended to address intersections projected to fall below its standard, including possible roundabout improvements.

WSDOT has also been strongly encouraging roundabouts for improvements on state facilities, Hendricks said, and has approval authority for projects affecting state highways.

The city will next finalize its transportation project list, compile the draft transportation element and continue public engagement before the transportation chapter is ultimately considered with the rest of Chelan’s comprehensive plan update.

Andrew Simpson: 509-433-7626 or andrew@ward.media